Richard Dapson

Richard Dapson
Biological Stain Commission

Ph.D.

About

68
Publications
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Introduction

Publications

Publications (68)
Article
We investigated physicochemical characteristics of dye lots sold as “alcian blue” using the Biological Stain Commission (BSC) precipitation test, differential scanning calorimetry, high performance liquid chromatography, thin layer chromatography and UV/visible spectroscopy. Four blue phthalocyanine dyes were detected in 11 commercial dye lots. The...
Article
Full-text available
For various reasons, histologists in several parts of the world have tried to replace hematoxylin and eosin with locally available plant dyes of the anthocyanin family. Blue or violet nuclear stains have been created by combining an anthocyanin with iron or aluminum ions at low pH. Obtaining a pink or red cytoplasmic counterstain, however, has not...
Article
Full-text available
The natural colorant, roselle, found in Hibiscus sabdariffa, has been used as a histological dye since at least 1976. As a simple extract roselle acts as a general red counterstain, but when treated with an oxidant and metallic mordant it functions as a useful blue nuclear-selective stain. In the past 40 years it has been assumed that oxidation is...
Article
Full-text available
Roselle is the common name for a mixture of anthocyanin dyes derived from the plant, Hibiscus sabdariffa. During the past two decades, a sizable, but conflicting, body of literature has supported the use of roselle as a biological stain, and more specifically as a substitute for hematoxylin for staining nuclei selectively. We review the literature...
Article
Alcian blue dyes are copper phthalocyanines with a variety of cationic side chains; they are useful for staining carbohydrate polyanions while avoiding staining of nucleic acids. The properties of the original alcian blue and of similar dyes with published chemical structures are reviewed here. Variation among samples submitted to the Biological St...
Article
Full-text available
Amyloid is a diverse group of unrelated peptides or proteins that have positive functionality or are associated with various pathologies. Despite vast differences, all amyloids share several features that together uniquely define the group. 1) All amyloids possess a characteristic cross-ß pattern with X-ray diffraction typical of ß-sheet secondary...
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During the 1860’s, Hugo Schiff studied many reactions between amines and aldehydes, some of which have been used in histochemistry, at times without credit to Schiff. Much controversy has surrounded the chemical structures and reaction mechanisms of the compounds involved, but modern analytical techniques have clarified the picture. I review these...
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Brazilin is a nearly colorless dye precursor obtained from the heartwood of several species of trees including brazilwood from Brazil, sappanwood from Asia and the Pacific islands, and to a minor extent from two other species in Central America, northern South America and the Caribbean islands. Its use as a dyeing agent and medicinal in Asia was re...
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During the 12 years from 2002 to 2013, the Trustees and laboratory personnel of the Biological Stain Commission (BSC) can claim many accomplishments. These accomplishments are itemized under 11 categories: continuous publication of the official journal, Biotechnic & Histochemistry; production of four special issues of Biotechnic & Histochemistry de...
Article
Quantitative structure activity relations (QSAR) models were developed to predict uptake and intracellular localization of probes or dyes in living cells. Many of the QSAR parameters used in such models are determined manually. Unfortunately, this requires a depth of chemical knowledge that biologists who wish to use these predictive tools do not n...
Article
The log P descriptor, despite its usefulness, can be difficult to use, especially for researchers lacking skills in physical chemistry. Moreover this classic measure has been determined in numerous ways, which can result in inconsistant estimates of log P values, especially for relatively complex molecules such as fluorescent probes. Novel measures...
Article
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Sirius red F3B (CI 35780, Direct red 80) is a polyazo dye used principally in staining methods for collagen and amyloid. For certification by the Biological Stain Commission, a sample of the dye must exhibit an absorption spectrum of characteristic shape with a maximum at 528-529 nm, a small shoulder near 500 nm and narrow peaks at 372, 281-282 and...
Chapter
IntroductionDenaturationPenetrationManaging Specimen QualityFixation with FormaldehyeOther Popular FixativesReferences
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The origins of repeated hematoxylin shortages are outlined. Lack of integration in the hematoxylin trade exacerbates the problems inherent in using a natural product. Separate corporations are engaged in tree growth and harvesting, dye extraction, processing of extracts to yield hematoxylin, and formulation and sale of hematoxylin staining solution...
Article
In this fifth issue of News from the Biological Stain Commission (BSC), under the heading of Regulatory Affairs, the BSC's International Affairs Committee provides more information from the meeting of the International Standards Organization ISO/TC 212 Committee that took place on June 2-4, 2008 at Vancouver, Canada. In addition, we give an update...
Article
One of the most sweeping changes in the dye industry since the advent of synthetic dyes grew out of the health risks associated with benzidine. Dyes made from benzidine and its derivatives were used around the world until adverse health effects become incontrovertible. Workers and family members of workers involved in production and use of benzidin...
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In June 2008, the Biological Stain Commission sponsored A Seminar on Dyes and Staining the purpose of which was twofold: first, to show that very useful information applicable to biomedical dyes and staining is available from unrelated disciplines and second, to summarize modern thinking on how dyes, solvents, and tissues interact to produce select...
Article
Full-text available
Carmine has been used in biological staining to demonstrate selectively nuclei, chromosomes or mucins, depending on the formulation. Throughout its history in science, complaints and frustrations have been expressed about dye quality. Inconsistencies in dye quality or identity have prevented thorough understanding of staining mechanisms and have ca...
Article
Full-text available
Although the mechanics of formalin fixation and antigen retrieval have been studied extensively and reviewed periodically, little attention has been directed toward conformational changes in target molecules. Formaldehyde changes the shape of tissue molecules by appending small hydroxymethyl groups to them. These adducts, in turn, can react with ot...
Article
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Over the past 13 years, glyoxal has become the leading alternative to formaldehyde as a histological fixative because of its low inhalation risk, faster reaction rate and selective control over crosslinking. The latter attribute is especially important, because most of the difficulties relating to use of formaldehyde-fixed specimens for immunohisto...
Article
Full-text available
Carmine is one of the original dyes certified by the Biological Stain Commission (BSC). Until now it has lacked both an assay procedure for dye content and a means to positively identify the dye. The methods for testing carmine in the laboratory of the BSC have been revised to include spectrophotometric examination at pH 12.5-12.6 to determine that...
Article
Full-text available
Nuclear fast red (CI 60760), also known as Kernechtrot, is commonly used in conjunction with an excess of aluminum ions as a red nuclear counterstain following histochemical procedures that yield blue products. The dye has also been used as a histochemical and colorimetric reagent for calcium. Unsatisfactory samples of nuclear fast red are encounte...
Article
Full-text available
Glyoxal is a popular substitute for formalin and in many ways acts like it, although there are significant differences. When formulated correctly, glyoxal fixatives produce superior morphological detail in only 1-9 h, but crosslinking does not occur. Glyoxal has a unique reactivity with arginine, producing a cyclic imidazole in place of the highly...
Article
Full-text available
Carmine is one of the few dyes currently certified by the Biological Stain Commission that is not assayed for dye content. Existing assay methods are complex and do not differentiate the three cochineal derivatives carmine, carminic acid and aminocarminic acid. The latter dye is relatively new to the food trade as an acid-stable red colorant and ma...
Article
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Staining of tissues by dyes is accomplished through various types of bonds, some of which have been poorly defined in traditional biological literature. Here, basic principles of bonding are reviewed to establish uniform terminology and definitions consistent with the field of chemistry. The concept of charge - its presence or absence, magnitude, e...
Article
Terrestrial salamanders of the genus Plethodon live in a world dominated by chemical-mediated senses. Little is known, however, about the histochemistry of the integumentary glands that produce chemicals used for communication and predator defense. We used histochemical staining techniques to identify the caudal integumentary glands in both male an...
Article
Alcian yellow and toluidine blue form one of the most popular non-silver methods for routine staining of Helicobacter pylori. Because of the shortage of Alcian yellow, a procedure with two new dyes is presented that duplicates the colors and contrast of the original stains. Hp Yellow stains neutral mucus pale to bright yellow in a Schiff-type react...
Article
Questions have arisen recently on the Histonet listserver about the properties of zinc formalin fixative. The advantage of zinc formalin over the usual formalin fixatives appears to be that zinc ions hold macromolecules in their native conformation via coordinate bonds, preventing the damaging crosslinkages that formaldehyde alone would create. The...
Article
First, it matters not a bit what others are doing, even if they are doing it with the full knowledge and permission of their wastewater treatment officials. This is because every treatment plant is different, and must set its own limits on chemical waste. Approval must be obtained from local officials. Getting permission from one's own group of off...
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The disposal of certain laboratory chemicals provides a challenge from a pollution-prevention perspective. Using substitutes, treating the chemical, and recycling can solve this problem. Recycling chemicals not only provides a pollution-prevention solution for the laboratory, but also cuts down on costs of materials and associated waste disposal. I...
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In Albuquerque NM, a novel, proactive pollution prevention plan helps biomedical laboratories reduce the volume of hazardous chemical wastes in the sewer system. Sewer agencies regulate heavy metals which are commonly used in reagents, cleaning products, fixatives, stains, and elsewhere in the laboratory. Laboratories can keep these wastes to a min...
Article
Full-text available
Neutral buffered formalin (NBF) has been the standard fixative in histopathology for many decades; however, new technologies and increasing time constraints have made this common fixative less widely applicable. The attributes of universal and ideal fixatives are reviewed and compared with those of NBF. On the strength of a growing body of literatu...
Article
Renal indices involving the relative thickness of the medulla and inner medulla were determined for Neotropical representatives of all New World bat families. Renal morphology in bats is primarily a function of diet and secondarily related to environmental dehydration pressure. Bats that are primarily frugivorous or nectarivorous possess kidneys wi...
Article
1. When feeding on figs (Ficus insipida), the bat Artibeus jamaicensis increases dietary sodium density while decreasing potassium density by primarily extracting and ingesting pulp juices rather than other parts of the fruit. 2. Based on urine osmotic pressure, these bats are uniformly dehydrated when they leave day roosts and become rapidly rehyd...
Article
Seven different commercially available mounting media, designed for permanent preparations, were tested spectrofluorometrically and viewed microscopically. Diatex and Pro-Texx had minimal fluorescence, but Diatex was difficult to use because of its viscosity. Permount showed variability in fluorescence intensity and emission wavelength in three lot...
Article
Seven different commercially available mounting media, designed for permanent preparations, were tested spectrofluorometrically and viewed microscopically. Diatex and Pro-Texx had minimal fluorescence, but Diatex was difficult to use because of its viscosity. Permount showed variability in fluorescence intensity and emission wavelength in three lot...
Article
A new theory, based on the hard and soft acid and base (HSAB) principle, is proposed to explain interactions among two (or more) dyes and tissues. Ions lie at specific loci on a scale of hardness/softness (H/S), depending on the spatial nature of their charge site. Oppositely charged compounds of similar H/S characteristics form stable bonds which...
Article
Basic concepts of chemistry, such as the atom, covalent bonds, ionic bonds, hydrogen bonds, oxidation, reduction, pH, acids, bases, and hard-soft acidbase (HSAB) theory are explained. Chemical reactions of formalin, heavy metal fixatives and alcohol with tissue components are discussed as well. Because most staining procedures involve charged subst...
Article
Most papers concerned with age-estimation technics contain procedural or statistical errors or omissions that hinder efforts to evaluate their accuracy and hence their worth. Eight common problems are cited: (1) reconciliation of variability in counts of annuli within an individual, (2) lack of known-age material, (3) inadequate statistical treatme...
Article
Lipofuscin accumulation in cerebellar Purkinje cells was studied in two natural populations of old-field mice (Peromyscus polionotus). Chronological age was estimated by assaying water-insoluble proteins in the eye lens. The number of fluorescent lipofuscin granules per cell was used as an index of physiological age. In both populations, lipofuscin...
Article
Over 5,000 deer (Odocoileus virginianus) were collected from 2 contiguous areas in South Carolina between 1965 and 1971. Age- and sex-specific survival rates were about equal in the 2 populations, but fawn production, age structure, and sex ratios differed markedly despite close proximity of the herds. Carrying capacity, population pressure, and de...
Article
Secretions from the gular gland of male molossid bats (Tadarida brasiliensis and Molossus bondae) and pararhinal glands of male big brown bats (Eptesicus fuscus) were analyzed histochemically. Proteins and phospholipids were apparently absent from secretions of the glands of all three species. Sebaceous portions of the gular gland of both molossids...
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1. 1.|In vitro thermal sensitivity (t.s.) of mammalian small intestine is significantly greater than t.s. of the gut of ectothermic vertebrates. In vitro contraction frequency (c.f.) of endothermic gut is an order of magnitude greater than ectothermic gut at equivalent temperatures.2. 2.|Gut contraction t.s. is generally consistent within a given o...
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When physiological condition is curvilinearly related to environmental conditions, the "op- timum" environmental condition is frequently determined by intersecting two straight lines. 2. Errors in this method are discussed, and a more precise method is suggested. 3. The curvilinear function is described by polynomial regression. 4. Optimum values o...
Article
Radiocesium content of adult male green treefrogs Hyla cinerea from a contaminated habitat is adequately described by a log normal distribution with mean 2.277 log10 pCi g-1 dry wt (189.2 pCi g-1) and variance of 0.031. There was significant negative correlation of body burden with body length and weight (p < 0.05), but the relationship lacked pred...
Article
The efficacy of nine solvents for oil red O was studied, with particular attention to staining intensity, specificity, and precipitation. The following solvents were used: Carbowax 400, triethyl phosphate, Tween 40, Tween 80, isopropanol, propylene glycol, ethylene glycol, ethanol propylene glycol, and ethanol ethylene glycol. Glycol based solvents...
Article
Levels of radiocesium contamination of the sediments of the stream bed, delta and associated floodplains of Steel Creek of the AEC Savannah River Plant are among the highest reported for a natural system. Desorption studies have shown that the radiocesium is not tightly held by the sediments. Fine particle silt and clay sediments averaged 170.47 pC...
Article
Full-text available
There are two types of granular glands in the skin of leopard frogs (Rana pipiens). Cellular glands produce fine intracellular granules rich in carbohydrate, carboxylic acids, tyrosine and sulfur-containing amino acids. Luminal glands consist of peripherally located nuclei with scant cytoplasm. Fine granular material in these glands resembles cellu...
Article
The tyrosine content of eye lenses of known-age old-field mice (Peromyscus polionotus) were analyzed colorimetrically. The soluble fraction increases linearly with age from 45 to 308 days, but thereafter is not related to age. The insoluble fraction varies curvilinearly with age to at least 750 days. Accumulation of soluble protein represents growt...
Article
Full-text available
An accurate age-estimating technique, based on biochemical changes in eye lens protein, was used to study age structures of six populations of the old-field mouse,Peromyscus polionotus. A new mathematical procedure permitted quantitative comparisons of these populations. Four inland populations had essentially the same median ages (75–84 days), max...
Article
Full-text available
The most accurate method known to data for estimating age of wild vertebrates involves biochemical assay of eye lens proteins. Laboratory procedures that may be unfamiliar to many ecologists are described in detail. The method is based on precise changes in the amount of insoluble lens protein, and consists of two procedures: obtaining the appropri...
Article
Full-text available
Histochemical characteristics of the integumentary mucous glands of the leopard frog (Rana pipiens) are described so that their role in water balance can be better understood. Mucus is acidic, due to its content of sulfate and carboxylic acids. The carbohydrate moiety contains periodate-engendered groups which are not in close proximity to acid rad...
Article
Age was found to vary with tooth wear in a curvilinear, not rectilinear, relationship. The apparent rapid elimination of adults from the population after the spring breeding season was due to a constant, age-independent mortality rate. Whereas most reproductive activity occurred in spring, scattered incidents of breeding were found throughout the y...
Article
CHANGES with age in the relative amounts of water soluble and insoluble proteins have been studied in cattle, humans and laboratory rats. The changes apparently result from oxidation of cysteine in the soluble portion and its incorporation as cystine in the insoluble protein1.
Article
Growth patterns in shrews were studied to learn if seasonal fluctuations in size occurred. Over 400 specimens were aged on the basis of tooth wear. When cranial height was analyzed by month of capture, seasonal, cyclic changes were evidenced. Average skull height varied from a maximum in the first spring of life, to a minimum during the winter, and...

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