Virus - Science topic

Restriction enzymes are common tools to compose genetically engineered plasmids in vitro. In laboratory circumstances it is possible to break DNA strands and recombine it with another strand.

However, I do not know whether such processes may happen spontaneously in cells that contain endonucleases and are co-infected with DNAs of different viruses? Or splitting and recombining DNA strands by endonucleases may only work with isolated endonucleases in laboratory settings?

Coronavirus vaccine.. What happens after the virus changes its configuration ? What will the live vaccine induce in our bodies? What will the immune response produce in our bodies ?

I'm working on microinjection. I wonder that how would- storage AAV2-Retro if it was not totally over in the pipette? Normally, we storage it in aliquots at -80. The virus I'm using now is left in the pipette. So, should I store it at -80 or -20? If it can be stored at +4, how long can it be stored? Finally, can I store AAV2-Retro with pipette?

52 till affected,death how and nos

Ernakulam Kerala kojijhor

Can you tell me affected nos of patients in this area and which action taken to prevent it.

Hi!

I need help with virus quantification and I am confused with the units. In some studies virus's titres are written as 10E5 TCID50/mL in other studies 5 log10 TCID50/mL. Is it the same?

Thank you

Hello, I've recently been studying Ancestral Sequence Reconstruction (ASR), attempting to infer ancestral sequences of viruses. I understand that this inference is constrained by factors like sample size and models, and represents a plausible sequence that may have existed. However, I'm curious about whether directly comparing these inferred ancestral sequences holds biological significance. Can they reflect the differences among the extant sequences from various lineages that were used to infer them?

Will the new mutated virus have the same effect as Corona virus as it did before?

Hello guy, I need your help to solve my problem in experiment. I got sample as culture cell line. I have to detect whether virus infection or not in this cell culture sample (pharmaceutics product). I should test the presence or not of RNA virus from bovine/porcine in these cell lines by quantitative real-time PCR method.

My plan is: I will find the specific sequence for these RNA viruses to design primer, probe and plasmid (that I will use as positive control when I running RT-qPCR, and make standard curve). In this case, when I perform RT-qPCR I need RNA or DNA to running.

My question here is: In this case, how can I isolate RNA or DNA of virus from culture cells? Or anyone have experience to perform this kind of experiment before can tell me what should I do in this case?

I have never do this kind of experiment before so I am so confused. Thank you so much for your help.

please mention the key differences and why best.

What type of proteins are those that make up virion particles? Same question is for ribosomal proteins.

Hello guy, I need your help to solve my problem in experiment. I got sample as culture cell line. I have to detect whether virus infection or not in this cell culture sample (pharmaceutics product). I should test the presence or not of RNA virus from bovine/porcine in these cell lines by quantitative real-time PCR method.

My plan is: I will find the specific sequence for these RNA viruses to design primer, probe and plasmid (that I will use as positive control when I running RT-qPCR, and make standard curve). In this case, when I perform RT-qPCR I need RNA or DNA to running.

My question here is: In this case, how can I isolate RNA or DNA of virus from culture cells? Or anyone have experience to perform this kind of experiment before can tell me what should I do in this case?

I have never do this kind of experiment before so I am so confused. Thank you so much for your help.

#SARSCoV2 is airborne - I am interested in finding the most recent / definitive research into its nature and protection from transmission. Thank you.

A patient with desminopathy (mutation Thr341Pro DES in a heterozygous state) with the progression of the disease has a decrease in taste and smell, immunosuppression, and an increase in IgA in the blood.

Oddly enough, but all this is characteristic of infections, including viral ones. For example, it is known that if the hepatitis C virus is not treated, then death will occur in 20 years.

In the identified case of late onset desminopathy, muscle weakness manifests itself at the age of 30, and death occurs 20 years after the onset of the disease.

I know the word to be for human children but Hess writes in 1971:

"Others reported substantial attenuation after 100 passages in rabbits (MENDES, 1962). Another attenuated lapinized strain of ASF virus recovered it&initial virulence when passaged a number of times in pigs (SANCHEZ BoTIJA, 1962).

Russian investigators (KovALENKO et al., 1965) have shown that kids 4 to 5 months old could be infected with ASF virus by intraperitoneal inoculation of infected blood. The animals developed symptoms in 6 to 25 days and one kid died after 36 days. Virus was found in the blood 6 days after infection but was no longer present after 30 days. It was present in the spleen after 36 days but not after 70 days. The disease was characterized by hyperthermia, diarrhea, severe emaciation and by lesions in the reticuloendothelial system. The virus was passaged 19 times in kids and appeared to adapt progressively to these animals causing damage to the reticuloendothelial system and accumulating in the spleen [1]."

1. Hess, W.R. African Swine Fever Virus. Virol. Monogr. Virusforsch. Einzeldarst. 1971, 9, 1–33, doi:10.1007/978-3-7091-3987-5_1.

I searched through the internet but in vain. Also, I could not find the article of Kovalenko, either in English or Russian.

Thank you in advance

I am after the sequence for the murine leukemia virus-derived MND promoter (myeloproliferative sarcoma virus enhancer, negative control region deleted, dl587rev primer-binding site substituted), MNDU3. Can someone help me out?

Thanks Karin

To date, the human cost of coronavirus (COVID-19) is more than 13 000000 infections, and more than 570000 death worldwide. The economic cost so far has been staggering. Many economies almost come to a halt. The impact on supply, demand, the financial market is affecting both larger and smaller firms. However, SMEs are at a disadvantage due to limited resources, existing obstacles in securing capital, and the span of time over which they can survive this pandemic compared to the larger firms.

How SMEs and new start-ups are going to handle this pandemic? Can they survive it or a great majority of them will go out of business? Should the government step in to help?

Since the start of the COVID-19 Pandemic, many governments and private organizations allocated large sums of money to fund projects dealing with various areas related to this virus. The vaccine is the most prominent area but detection, caring and monitoring of the patients revealed that the current medical equipment is not adequate and sufficient. Are these funding going to lead to invention or innovation? have you seen any report of innovation in medical technology in your community?

Hi,

I am introducing the strategy briefly which I follow to infect the MC38 cells with harvested lentivirus media from HEK293T cells at 24 and 48h.

1. First, MC38 cells are cultured in 60mm culture dish and when cells growth reach at 70% confluent, I change the previous media to virus medium for transduction with the help of polybrene (8ug/ml).

2. After that when cells growth is completed, I subculture the first-time infected cells and again transduction is done with viral media for second time when cells volume is 50-70%. Then the dishes are kept on incubator for overnight or more based on cells growth.

3. Finally, GFP positive cell percentages are determined by flow cytometry after proper growth. The problem is that GFP% is very low (<10%) although the GFP% of HEK293T cells are around 30%.

What should I do to increase the efficiency of infection?

Do somebody try to package virus >12KB plasmid? What is the efficiency?

Good day everyone, Please I am doing transfection/ transduction, I want to check the MOI of the virus and at the same time perform viral concentration, but i am stuck up with the steps. please can some assist me with relevant information ?

I am looking for a cell lineage infected by herpes simplex 1 virus.

PeiR is a lytic enzyme which is a methanogen virus that infects Methanobrevibacter ruminantium M1. Do all protease have active sites, if so how do I find it with the sequence only.

Hello everyone,

I am in the doing viral injection (hamilton and automatic pump) with AAV-mcherry targeting piramidal neurons in mouse aging from P40 to P50. After 2 to 3 weeks, I performed optogenetics stimulation, then after having the brain removed, soaked in formalin and fixated for at least 48h, I checked the viral expression with fluorescence microscope.

Here's the point: out of 10 trials, 4 times I didn't find any trace about the viral expression. I have checked the whole brain, but still zero. We are talking about zero level expression. On the other hand, in 6 experiements I have strong and proper expression.

In my experimental routine, I had 2 injections per day (2 mice). On the same days, I withdraw the virus out of the same small eppenderf tube each time for one animal. Between the two viral injections, the virus is kept soaked in ice in a dark water proof container.

I am sure the virus was injected (I saw the virus level in the glass capillary lowering). As always, I have waited 10 min before needle removal.

What could have happened in those 4 trials with no expression? Is the virus contained in the eppendorf damaged (at least in some of them)? I really don't know what to think right now.

Any help would be much appreciated.

I am writing a review article, I want to know if it is common to use a general 3d structure of a virus in the publication. (of course by mentioning the reference)

Which of the following is a characteristic symptoms of plants infected with phytoplasma that makes it different from a virus?

Can lentivirus vectors be directly transfected without packaging the virus？

In focus reduction neutralization assays, we apply a virus and serum mixture to a monolayer of cells. After infection, incubation, fixing, and staining we count the number of foci (formed from staining proteins released by dead cells) in order to determine if the sera applied to the cells blocked viral infection. We have been doing these assays for years and all of a sudden there has been a lot of variation in the virus phenotypes in our assays. We have a consistent incubator temperature, we have used the same cell line (vero-81 cells), same virus strains, media, etc. The only difference is different sera samples. Can anyone explain this?

Hello,

How would I determine the # of amino acid residues in a sequence? Is there an easier way to count them?

I'm trying to calculate the molar extinction coefficient for AAV. The MW of the AAV is 3740000 Da.

ϵ(280) (M−1 cm−1) = (#Trp)(5,500) + (#Tyr)(1,490) + (#cystine)(125).

Thank you!

Dear Researchers,

I need 2 ml of NZ2 strain ORFV virus for my student Ph thesis. Could you send us, buyer pay.

My address:

Prof.Dr. Mehmet KALE

Department of Virology

Faculty of Veterinary Medicine

Burdur Mehmet Akif Ersoy University

Burdur, Turkey.

E-mail: drmkalex@yahoo.com or mkale@mehmetakif.edu.tr

Regarding to the question (covid-19 is a natural virus or created by human) who we can realize the fact of this issue?

Any link will also be helpful.

Thank you

On 4 May 2023, the World Health Organisation lifted the state of global epidemiological emergency associated with Covid-19. The WHO declared that Covid-19 no longer posed a public health, human health threat on a global scale. The WHO introduced the state on 30 January 2020, and after more than three years, the state was lifted. But the key point is that it was lifted as an epidemiological risk 'only' on a global scale and not as a direct recommendation for individual countries. Well, in individual countries, the levels of infection and mortality, although significantly lower than in 2020, are still occurring as part of local, successive, seasonal increases in infection with specific types of relentlessly emerging successive virus strains, and are significantly different in terms of the comparative analyses carried out. Globally, almost 7 million people have died according to Covid-19 death statistics and in more than 90 per cent of cases in combination with the presence of various co-morbidities. In Poland, these deaths were 120 000 with 5.5 million diagnosed infections and more than 250 000 excess deaths. In Poland, the Covid-19 epidemiological emergency is due to be lifted at the end of June 2023. In relation to this, is there still research being conducted by the WHO on the secondary effects of the Covid-19 pandemic? The 2018 Spanish flu was an avian flu that passed to humans. This was not the only such case in which a virus that causes disease in specific animal species started to infect and cause specific diseases in humans as well. It may have been similar with the SARS-CoV-2 (Covid-19) coronavirus, because before it started infecting humans it had previously developed in certain bat species, among others. It is likely that this virus acquired new features after the modification of its genome applied in laboratories, its effect was enhanced, it escaped from the laboratory and also started infecting humans. According to mathematical models of forecasting, which take into account population growth, increased population density in urban areas, low levels of sanitation in many parts of the world, low levels of availability of clean water in many economically poorer countries, the rate of creation of new strains of influenza viruses, coronaviruses, RSV, etc., which attack humans and certain animal species, the progressive process of global warming, climate change on different continents, increased environmental pollution and the impact of toxic waste pollution on human health, etc., it is likely that the virus will become more widespread in the future.

In view of the above, I address the following question to the esteemed community of scientists and researchers:

What do you think about this topic?

What is your opinion on this subject?

Please respond,

I invite you all to discuss,

Thank you very much,

Best wishes,

Dariusz Prokopowicz

Reply or response should be supported by valid reference or reasoning.

Should there be vaccination in the face of a disease outbreak in a population where there are disease cases and obviously infected individuals?

WHO defines vaccination as, "Vaccination is a simple, safe, and effective way of protecting you against harmful diseases before you come into contact with them." (https://www.who.int/news-room/questions-and-answers/item/vaccines-and-immunization-what-is-vaccination).

In Chapter 4.18 of OIE - Terrestrial Animal Health Code - 10/08/2022, you can do a Ring vaccination around a herd of infected animals to contain the disease in animals susceptible to the disease (certainly still not infected).

In the book, "Trends in Emerging Viral Infections of Swines, Kyoung-Jin Yoon, ‎Jeffrey J. Zimmerman, ‎Antonio Morilla · 2008", it is stated on page 162 Section 5 on Classical Swine Fever Virus that, "Vaccination in Infected herds helps spread field virus". and also, "In endemically infected, vaccinated herds, there is selection for low-virulent CSFV strains".

Please share your views with references if any.

Hello.

Is there any option to design positive control other than using MEGA software? Does anyone know or expert using the MEGA Software?

What is the reason that viruses aggregate in aqueous solution ??

Has any got experience packaging MSCV vectors with large cargo? Im in the final stages of plasmid design and so far the size is ~8.8kb.. I'm concerned the virus will fail packaging.

The highly-infectious disease is similar to Ebola, with symptoms including fever, muscle pains, diarrhea, vomiting, and, in some cases, death through extreme blood loss.

Hundreds of people have died from the virus in recent years, almost all in Africa.

According to the World Health Organization (WHO), on average, the Marburg virus kills half of the people it infects, with previous outbreaks killing between 24% and 88% of patients.

The virus was first identified in 1967 after 31 people were infected and seven died in simultaneous outbreaks in Marburg and Frankfurt in Germany and Belgrade in Serbia.

The outbreak was traced to African green monkeys imported from Uganda.

But the virus has since been linked to other animals.

I'm trying to simulate virus and nanoparticle interaction. I wonder what software can run this types of simulation? can I use VMD ??

Covid news – live: Cases soar again in India as doctors warn of ‘new symptom’

A new coronavirus strain dubbed Arcturus appears to be driving a surge in Covid-19 cases in India, prompting the country to resume vaccine production and sparking fears it could lead to a rise in cases in the UK and elsewhere.

India on Friday recorded 11,109 new Covid infections, the biggest jump in almost a year. The country’s active case count is now up to 49,662.

The XBB.1.16 strain, a sub-variant of Omicron, has been found in 22 countries, including Singapore, Australia, the UK and the US. Research indicates Arcturus could be one 1.2 times more infectious than the last major sub-variant, making it likely to become the dominant strain.

The spread of the strain, first detected in late January in India, is worrying experts, as it seems to exhibit unique symptoms in children, one of which is conjunctivitis.

The symptoms of the variant include high fever, cough, and “itchy” conjunctivitis or pinkeye, according to Vipin Vashishtha, a paediatrician and former head of the Indian Academy of Pediatrics Committee on Immunisation.

source: https://ca.yahoo.com/news/covid-news-live-cases-soar-075336169.html

COVID-19 and Influenza Activity

April 2, 2023 to April 8, 2023

These images provide a high-level assessment of respiratory virus activity in Ontario. Provincial percent positivity can be used to provide an estimate of the intensity of circulating viruses in the province. Percent positivity for the most recent week is used to assign influenza and COVID-19 to either a low, moderate, high or very high category. Weekly indicator change was determined by considering a combination of indicators (see Technical Notes). For further details, please refer to the Respiratory Virus Overview in Ontario report.

source: https://www.publichealthontario.ca/en/data-and-analysis/infectious-disease/covid-19-data-surveillance/covid-19-data-tool?tab=overview

Other viruses are routinely isolated, but not SARS-CoV-2.

HeLa cells were resistant to TGEV infection. However, when I incubate the Hela cells with about 1 MOI of TGEV, a lot of cells died two days after incubation. Why does this happen? is it due to the stress from this virus?

Hello Everyone

I have been working on 14 different virus strains to be detected utilizing TaqMan Probes. Although I get good results in Singleplex assays with the almost same Ct for all samples, in multiplex assays 3 types have higher CTs (more than 5 cycles), Do u have any suggestions to overcome this issue? the plasmid copy number, primer-probe concentration, and qPCR probe Master mix are the same.

There are several health and physical problems, after recovering from the Corona virus, and I need research links on this topic, thank you very much for all

I am conducting Avian Influenza virus detection by real time rt PCR.

I did 4 target AI genes and 4 primer probe sets for PCR.

(H7 HA, H5 HA, NP and M target gene)

I run real time 4 time individually for that 4 target genes.

The result came out non-similarity.

(For Example,

In Sample no 1, H7 HA and H5 HA amplified (positive) but not amplified in NP gene and M gene .

In Sample no.2., result came all 4 gene were amplified.

In Sample no.3 NP gene and M gene and H5 HA gene came out positive result.)

How can I understand the nature of antigenic protein surfaces of virus and detection system of real time PCR.

Even though the same sample and same virus, can different results by using different target gene?

Hello,

I have a question regarding qPCR efficiency calculation.

Is it correct to talk about PCR efficiency if I perform a serial dilution of sample that containing an unkwon concentration of the viral particles?

I usually read that the serial dilution should be done from a known concentration of the extracted DNA. But I have stool samples where the amount of virus is unknown and the dilution was made from the sample stock. Afterwards the DNA was extracted and PCR was run.

When I calculate the slope of standard and the efficiency. Can I then talk about PCR efficiency?

Thank you for your feedback!

We are testing virus titer, and have to dilute the virus stock at 1:10,000 (Dilution A) and 1:20,000 (Dilution B) to run qPCR as templates. Then convert the diluted titer to dilution corrected titer. However, the conversion from A or B is not the same value, showing a big difference. I guess the problem is about dilution. Is there any best strategy procedure to complete the dilution within 3-step? Thank you.

The thawing of permafrost, which has been present for thousands and millions of years in areas near the Arctic Circle, mainly in the Arctic, caused by the accelerating process of global warming, will result in the release into the atmosphere of thousands and possibly millions of tonnes of hitherto frozen methane, a gas that is many times more greenhouse-generating than CO2, which will result in a significant acceleration of the already rapid process of global warming. However, this is not the only very dangerous effect for human civilisation and for the state of the planet's biosphere of the progressing process of global warming, a process which has been taking place since the first industrial revolution, i.e. since the 18th century. Among the significant negative consequences of the increasingly rapid global warming process triggered by the industrial revolution based on the dirty energy of burning fossil fuels is the increase in the risk of a future pandemic caused by viruses emerging from the thawing of the permafrost in areas near the planet's Arctic Circle. These viruses emerged and were frozen many thousands and perhaps millions of years ago, i.e. when there was not yet a modern species of homo sapiens on planet Earth. Therefore, humans may not be immune at all to these strains of different types of viruses that functioned on the planet many thousands of years ago. In addition, the existence of many species of both wild animals and farmed livestock may also be threatened if thawing viruses from many thousands of years ago prove to be completely unfamiliar to the immune systems of said animals. According to CNN media reports, there are virological research laboratories currently working on revived viruses taken from thawing permafrost. These revived viruses are referred to in the media as "zombie viruses". In addition, high summer temperatures have thawed the corpses of people who died and were buried in cemeteries many years ago, as well as animals, from whose thawing bodies pathogenic strains of viruses and bacteria have emerged. The thawing of the permafrost in recent years, for example, has been identified as a major source factor in the occurrence of the anthrax epidemic in Siberia, because the high temperatures experienced in Siberia for the first time in many thousands of years allow viruses and bacteria to be released from human cemeteries and animal corpses, i.e. micro-organisms that functioned thousands of years ago and which may be particularly dangerous to humans and animals living on the planet today.

In view of the above, I address the following question to the esteemed community of scientists and researchers:

What is your opinion on this subject?

Please respond,

I invite you all to discuss,

Thank you very much,

Best regards,

Dariusz Prokopowicz

Hello,

My topic of research is Avian Leukosis Virus (ALV). I have noticed that there are some old research papers that showed that when injecting chicken cells infected with Rous Sarcoma Virus (a close relative) in the brain, tumors would appear in non-avian animals such as mouse or monkeys. And those tumors are of host origin.

Basically they conclude that a virus specific to birds, that has not been reported to infect non-avians, can cause disease if introduced in the brain through experimental methods.

I haven't found current papers on this issue so my question is: Do we know of a mechanism that explains this? or is the methodology flawed? Do you know of a similar phenomenon in other viruses?

I harvested a virus. When I did plaque assay to titer it, I did duplicate and the titer was different. How can I take one of them? Will I average them? The concentrations were 4.50E+05 and 2.50E+05 PFU/ml.

I will do a PRNT test with these virus. Therefore, It is important to know its titer as accurately as possible! Any help would be greatly appreciated!

I have two DEG sets for 2 disease conditions (from mild to severe condition) of the same viral infection. When I look at the common gene from these two sets of DEGs, I found that some genes show opposite expression among these two conditions ( Like a gene downregulated in mild but up-regulated in severe or vice versa). So what I want to know is that,

1) If this phenomenon is normal in viral infection??

One of the most prevalent emerging pathogen that has turned into a public health issue in the recent years until now, is the virus that caused COVID-19 pandemic, known as the SARS-CoV-2. How may this virus potentially affect blood donations, and what measures may be taken by the blood bank to ensure the recipients' safety?

Which viral infection might be more severe?a transported virus from an animal to a human or a virus directly invade human?

I have been infecting L929 cells cultured in 6-well plates a few times now with samples containing VSV (samples are olfactory bulbs of mice that were inoculated with VSV), but I do not see any clear and visible plaques. This is weird to me since VSV effectively infects olfactory structures and we know it resides in the olfactory bulb. It can be attributed to biological differences (i.e., some animals just don't have detectable virus), but I have run many samples now and they are showing the same pattern, which is the lack of plaque formation.

The supernatant containing the virus from the samples is tenfold diluted and a range of 10^3 to 10^5 is tested at first. I do not see cell death (basically a clear monolayer of Coomassie blue staining at the end), so that rules out the possibility that the viral concentration is too high. I DO, however, see random, singular plaques here and there, which makes me think that something in the protocol is hindering the virus. See image attached for what plates generally look like.

Things I can think of:

- Cell confluency: could a lower confluency (70-75%) interfere with plaque formation?

- The culture medium for L929 cells I use includes antibiotics (Gentamicin); could this interfere in any way with viral infectivity of cells?

- I use 100uL of viral dilutions to infect plates: could this be too little?

- I infect the cells for 1hour in the incubator with shaking every 15 minutes: should I go for longer, although this is the standard?

- The overlay I use is x2DMEM:Agarose (I tried 0.6% and 1% Agarose)

- I boil the agarose in the microwave but then cool it down with cold x2DMEM before overlaying. I don't think it is too hot for the cells because if it was I would see big white stretches on the well indicating cell death or lifting.

- 3:1 Methanol:Acetic Acid is used as a fixative

That's all that comes to mind. I would appreciate any suggestions!!

Someone asked me like bacteria and archea humans have this kind of system CRISPR Cas ? imaginary idea is that righr or wrong?

I propagated the IBDV virus in the SPF eggs via the CAM route. The amount of harvested virus is limited so I want to ask if is there anyone with experience in doing realtime PCR instead of doing actual titration in eggs.

Hospital information systems (HIS) can be used to assist in the prevention of COVID-19 by tracking and managing patient information, monitoring outbreaks, and supporting communication between healthcare providers. For example, HIS can be used to track COVID-19 cases and contact tracing, facilitate virtual consultations and telemedicine, and assist in managing the distribution of resources such as personal protective equipment. Additionally, data from HIS can be used for public health surveillance and research to help understand and control the spread of the virus.

Dear RG community

I am writing the final paper of my Ph.D. thesis.

My final contributions are related to each other; I wanted to express both of these contributions in one article. Still, the number of pages increased significantly, so I want to publish the article in two parts. The first part and the second part, do you think this is possible?

I wanted to know what the protocol for a two parts article is.

I would be happy if you could explain how to write an article in two separate parts.

According to the structure of morbiliviruses, the M protein is located on the inner surface of the virus envelope. However, It can binds to the RNP complex and the intracellular regions of the surface glycoproteins. So, Is it considered as a membrane-anchored protein?

Does anyone know of a vendor who carries Cricket Paralysis Virus (CrPV)? We want to use it as a positive control virus for the S2 cell line. Thanks for any leads.

I am trying to infect EO771.lmb cells with lentivirus to express luciferase and Tdtomato. My cells are not expressing anything. I tried spinning the virus for 90 min with media+polybrene, but it did not work.

If anyone has any ideas, please let me know. Thank you

Can someone recommend a good solution and tube material to freeze aav2/9 in a -80C freezer? Is a cryoprotectant required?

We currently froze our AAV product in DPBS(+Cacl2,+MgCl2) into a cryovial but I've been reading articles that recommend all sorts of freezing methods.

I used DnaSP software to perform a nucleotide diversity analysis on a viral alignment file. After observing the data I saw that some positions have high values (0.79) and some positions have lower values (0.42). So what is the probable explanation for this?

We have been using PEG-8000 (10%) and NaCl (0.5 M) precipitation for concentrating phage samples before ultracentrifugation and for some of them, we got a really viscous solution after PEG precipitation. Adding DNase I has not helped. Why this high viscosity and what to do to get rid of it? Using samples as they are for ultracentrifugation gives no visible virus bands.

I tried using Phaster.ca and PhiSpy for phage detection in the bacterial genome

They showed a completely different result for regions and the virus identified.

Do you have the same experiences and could you share your suggestions, please?

Thank in advanced!

I would like to recover viruses from ground water to do metagenomic sequencing.

From my reading I found the researchers used cellulose nitrate filter membranes. In Egypt the available filter membrane is polycarbonate membrane filters, is there is anyone tried before polycarbonate? and what are the results after DNA extraction?

Also, are there other methods for virus recovery from water?

I transfected Lenti-X293T cells with a plasmid containing EF1-α promoter and Takara's VSV-G packaging kit. However, the titer and the transfection rate was low compared to a plasmid containing CMV promoter, using the same protocol. I am aware that EF1-α had a weaker expression than CMV in HEK cells, so that could explain the low titer.

I tried to increase the transfected plasmid amount by using 293fectin to transfect 5 ug of plasmid, in addition to the 7 ug transfected by the packaging kit as recommended by Takara, but the titer did not reach the level of a plasmid with CMV promoter.

Did anyone have problems with EF1-α in lentivirus production by Lenti-X293 T cells? Is there any way I can improve the virus titer?

Hi,

Dear researchers,

spike protein and nucleocapsid of SARS-CoV-2, which preferred to be targeted by drugs? Why?

Hello Scholars,

I am an undergraduate at the University of Cross River State, Nigeria currently pursuing a microbiology program. For familiarity and enhanced understanding of the course, I wish to seek recommendations on the virtual/simulation laboratory software that would be very helpful to me and my colleagues. With my interest in research too, I will be pleased if a research simulator is recommended to help widen my understanding of Microbiological research.

Your recommendations would go a long way to significantly contribute to my academic career as well as my colleagues.

Thank you

Cherish your feedback.

I am titrating lentivirus using Jurkat Cells. I transduced 250,000 cells with .05ul/.00005ml of undiluted virus in 1ml of RPMI media. We analyzed the fluorescence using Flow after 72 hrs (13.29%).

Which formula should I use?

Formula 1: (Number of cells transduced on day 1 x Percent fluorescent)/(Virus volume in mL)

Formula 2: ((Number of cells transduced on day 1) x (Percent fluorescent/100))/(Volume of undiluted virus Added (ml))

With formula 1, the titered amount will be: 664.5 X 10^8 TU/ml

With formula 2, the titered amount will be: 6.645 X 10^8 TU/ml

Formula 1 does give a huge titration number, but this is the formula I have found online everywhere.

Does this concentrated virus make sense?

I attached my protocol, maybe it is something wrong with it. Our lab have already ordered New MDCKs, but it still the same, I will be very grateful for any advise.