Angel Medina

Publications (41) View all

• Article: Comparison of different bead-beating RNA extraction strategies: an optimized method for filamentous fungi.

  Gonçalo M Leite, Naresh Magan, Ángel Medina
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  ABSTRACT: Molecular studies, especially in relation to the activity of secondary metabolite gene clusters, require the ability to extract good quality RNA from fungal biomass. This is often hindered by the cell wall structure and endogenous RNase activity in filamentous fungi. There is thus a need for rapid methods for the extraction of good quality RNA for use in microarrays and for quantitative PCR assays. The objective of this study was to examine the use of different systems for the high throughput method to extract intact RNA from filamentous fungi. Two bead beating systems with different motion patterns and speed capacities were tested in the development of the extraction protocol. They were evaluated based on the total RNA yield and overall RNA quality. The high speed bead beating with glass beads associated with an automated purification method gave more than three times higher total RNA yields with less than a quarter of the amount of mycelium required. Furthermore the integrity and overall quality was conserved, with RNA Quality Indicator (RQI) numbers consistently >7.5. This method also reduced cross contamination risks and kept RNA handling to a minimum while still being capable of multiple sample processing, reducing the time required to obtain RNA from filamentous fungi.
  Journal of microbiological methods 03/2012; 88(3):413-8. · 2.43 Impact Factor
• Article: Comparison of three different C18 HPLC columns with different particle sizes for the optimization of aflatoxins analysis.

  A Medina, N Magan
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  ABSTRACT: In this work we compared the performance of chromatography columns with particles of 5 and 3 μm with the new 2.7 μm solid core particles for the analysis of aflatoxins B1, G1, B2, and G2 using trifluoroacetic acid pre-column derivatization. Three different columns have been used and chromatographic parameters as retention time, resolution, limit of detection (LOD), limit of quantification (LOQ) were obtained from all of them and compared. The results show that comparing with the traditional columns, shorter columns (100 mm × 4.6 mm) with the new solid core particles are suitable for the analysis of these mycotoxins and allowed the reduction of the analysis time by 45.5% and 33.3% with respect to columns with particle size 5 μm (150 mm × 4.6 mm) and 3 μm (150 mm × 4.6 mm) respectively, without any detrimental effect on performance. This leads to the reduction of the analysis costs by saving on organic solvents and increasing the total number of analyses per day. The capability of these columns for analyzing samples, in different culture media, was assessed by analyzing different samples from: yeasts extract sucrose medium, corn meal agar medium and fresh hazelnut media.
  Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 02/2012; 889-890:138-43. · 2.78 Impact Factor
• Article: Impact of environmental factors on growth and satratoxin G production by strains of Stachybotrys chartarum

  S. Frazer, J. Pestka, J. Kim, A. Medina, D. Aldred, N. Magan
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  ABSTRACT: Export Date: 8 August 2012, Source: Scopus
  World Mycotoxin Journal 01/2012; 5(1):37-43. · 1.45 Impact Factor
• Article: Food security, climate change and mycotoxins

  N Magan, D Aldred, A Medina
  Quality Assurance and Safety of Crops & Foods 01/2012; 4(3):145-145. · 0.64 Impact Factor
• Article: Comparative study of water and temperature relations of growth and T-2/HT-2 toxin production by strains of Fusarium sporotrichioides and Fusarium langsethiae

  M. Kokkonen, A. Medina, N. Magan
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  ABSTRACT: Export Date: 14 February 2013, Source: Scopus
  World Mycotoxin Journal 01/2012; 5(4):365-372. · 1.45 Impact Factor