Wright's as A Differential Spore Stain

A method of differential spore staining utilizing Wright's stain diluted one to five in a phosphate buffer solution of pH 7.6 and following the general technic of the Dorner method is outlined. Spores are stained a deep blue while the cytoplasm of the sporangium is stained a pinkish red.     

Wright's as A Differential Spore Stain

A method of differential spore staining utilizing Wright's stain diluted one to five in a phosphate buffer solution of pH 7.6 and following the general technic of the Dorner method is outlined. Spores are stained a deep blue while the cytoplasm of the sporangium is stained a pinkish red.     

Improved Stability of Methanolic Wright's Stain with Additive Reagents

Additive reagents have been investigated to improve the stability of methanolic Wright's stain. The addition of ammonium halides, monoalkyiamine hydrochlorides, dialkylamine hydrochlorides or trialkylamine hydrochlorides to methanolic Wright's stain was found to enhance the stability of stain components in methanol. No change in performance is observed with these additives present. Random precipitation in the stain solution was still observed with the addition of ammonium halides and monoalkyiamine hydrochlorides. No precipitation was found in stain solutions containing hydrochlorides of most dialkylamines and trialkylamines. Of the compounds evaluated, 0.6% diethylamine hydrochloride added to methanolic stain solutions produced the most desirable overall results. Mechanisms of stabilization and precipitation in these stain solutions are proposed, Essentially, separation of the thiazine-eosinate ion pair through interaction with an appropriate additive increases stain stability. The solubilities of thiazine-eosinate or additive cation-eosinate ion pairs in methanol determine the formation of precipitate in such stain solutions.     

Improved Stability of Methanolic Wright's Stain Solution with Dual Additives

Degradation of methanolic Wright's stain solutions was greatly diminished with the addition of diethylamine hydrochloride and dimcthylamine hydrochloride as costabilizers. Precipitation problems were eliminated by the dual additives. The stabilized stain solutions demonstrated good staining performance on blood smears. Methods for predicting the shelf life using calculated analytical parameters are described. Using these methods, the shelf life of a control stain solution was predicted to be 0.7 years; predicted shelf life was more than tripled with the addition of diethylamine hydrochloride and was increased approximately 27 times with the addition of both diethylamine hydrochloride and dimethylamine hydrochloride.     

Wright's Stain for Chloroplasts and Tissue Spreads

Wright's stain, including the entire Wright method as used in hematology, is applicable to fresh animal and plant tissues which may be spread with rapid drying. Particularly are the chloroplasts and vacuole plastids of Nitella well prepared by: pricking open a blotted, uninjured (streaming) cell upon a dry slide, thus bursting out both chloroplasts and other plastids which spread themselves; further teasing of more plastids from the cell membrane upon an adjacent dry region of the slide. Also Tunicate zooids blotted dry in transference to a slide may be torn open and the various tissues teased and lifted about on the slide with excellent spreading of cells. Rapid drying with gentle heat, well timed fixing and staining and differentiation all contribute to results which not only show normal cellular differentiations but which are very valuable in showing experimental cytological changes.     

The Status of Wright's Stain and Some Suggestions as to its use

A questionnaire was sent to a number of the larger hospitals and laboratories of the United States in order to determine the degree of satisfaction experienced in employing Wright's stain. From a survey of the answers received, there seems little justification for poor results with this stain. It is probable that the great majority of unsatisfied users work in laboratories where the stain is used so seldom that proper manipulation is not always attained. The writer offers a few simple, but very important precautions to be observed.     

The Status of Wright's Stain and Some Suggestions as to its use

A questionnaire was sent to a number of the larger hospitals and laboratories of the United States in order to determine the degree of satisfaction experienced in employing Wright's stain. From a survey of the answers received, there seems little justification for poor results with this stain. It is probable that the great majority of unsatisfied users work in laboratories where the stain is used so seldom that proper manipulation is not always attained. The writer offers a few simple, but very important precautions to be observed.     

A Modified One-Step Trichrome Stain for Demonstration of Fine Connective Tissue Fibers

Gomori's one-step trichrome procedure was modified to improve coloration of fine connective tissue fibers. Paraffin sections from tissues fixed in alcohol, acetone, Zenkerformol, 10% formalin, Kaiserling's or Carnoy's fluid were mordanted 1 hr at 56 C in Bouin's solution, stained 1 min in a trichrome solution (chromotrope 2R-phosphomolybdic acidaniline blue WS) adjusted to pH 1.3 with HCl, rinsed in 1% aqueous acetic acid, dehydrated and covered. Collagen, reticulum fibers, basement membranes, ring fibers around splenic sinuses, intercalated discs in cardiac muscle and cartilage were colored blue. Nuclei, cytoplasm, fibrin, muscle fibers and elastic fibers were stained red. Pretreatment of sections with Bouin's solution enhanced the affinity of tissues for chromotrope 2R and was found essential for satisfactory coloration of material fixed in alcohol, acetone, formalin or Carnoy's fluid. Because this method does not require differentiation, it gave uniform results even in the hands of inexperienced laboratory trainees. No fading was observed in sections stored for more than 8 yr.     

Quad-Type Stain for the Simultaneous Demonstration of Intracellular and Extracellular Tissue Components

This technic for the simultaneous demonstration of several different tissue components works equally well on invertebrate and vertebrate tissue if they have been treated with nonchromate fixatives Sections 4-7 μ thick are stained 30 min in 1% Alcian blue, then treated with alkaline alcohol for 2 hr. They are stained in Verhoeff's hematoxylin for 4-6 hr, and rinsed in alcohol; stained in woodstain scarlet-acid fuchsin for 3 min, decolorized in 5% phosphotungstic acid for 20 min and finally stained 5-8 min in alcoholic saffron. Collagen and bone are stained yellow; elastin, myelin and nucleic acids, purple to black; muscle, chitin, cytoplasm, fibrinoid and acid secretion, bright red to lavender; ground substances and mucus, blue-green. Fibrous connective tissue, cartilage, bone and glandular epithelia are exceptionally well demonstrated by this method. Slides stained in this manner are well suited for color photomicrography and as demonstrations in the classroom.     

An Orcein-Oil Red O Stain for Concomitant Demonstration of Elastic Tissue and Lipid

Orcein, 0.5% in 50% isopropanol, 0.5-1 hr, followed by saturated oil red O in isopropanol diluted 3:2 with distilled water, 10-15 min, was used to demonstrate lipids and elastic tissue simultaneously in 10 μ frozen sections of formalin-fixed aortas of the wild African buffalo, showing atherosclerotic lesions. A comparison was made with the oil red O-aldehyde fuchsin (AF) method of Kwaan and Hopkins (Stain Techn., 39: 123-5, 1964) and the resorcin fuchsin (RF)-oil red O method of Lillie (Histopathologic Technic and Practical Histochemistry, McGraw-Hill, 1954), but both gave marked background staining by AF or RF that obscured the smaller deposits of lipid. Sudan IV could be substituted for oil red but did not demonstrate many of the finest deposits of lipids. Sudan black, in combination with orcein, AF or RF, was very satisfactory for demonstrating lipids but obscured many elastic fibres. Sudan dyes I, II, III, brown, blue, and green, with orcein, AF or RF, showed less contrast between lipids and elastic tissue or failed to stain the lipids adequately.     

The Mechanism of Stain Action with Basic Dyes

The chemical theory of staining is discussed in the light of recent discoveries respecting the mechanism of the reaction of basic dyes with substances of an acid character. It is pointed out that staining may result through the formation of addition products as well as through the formation of dye salts.     

The Mechanism of Stain Action with Basic Dyes

The chemical theory of staining is discussed in the light of recent discoveries respecting the mechanism of the reaction of basic dyes with substances of an acid character. It is pointed out that staining may result through the formation of addition products as well as through the formation of dye salts.     

The Peracetic-Orcein-Halmi Stain: A Stain for Connective Tissues

A selective stain useful for the study of connective tissues is described. The stain demonstrates elastic and oxytalan fibers as well as fibrils in mucous connective tissues previously undescribed. Reticular fibers are not stained. The stain may be used on sections that have been fresh frozen or fixed in formalin or ethanol. Sections are deparaffinized, washed in absolute ethanol, oxidized in peracetic acid 30 min, washed in running water, stained in Taenzer-Unna orcein 15 min, 37°C, differentiated in 70% ethanol, washed in running water, stained in Lillie-Mayer alum hematoxylin 4 min, blued in running water, and counterstained 20 sec in a modified Halmi mixture of 100 ml distilled water, 0.2 gm light green SF, 1.0 gm orange G, 0.5 gm phosphotungstic acid and 1.0 ml glacial acetic acid. Sections are rinsed briefly in 0.2% acetic acid in 95% ethanol, dehydrated and mounted.     

The Combined Perls-Hematoxylin-Eosin Stain

To provide a routine check for the presence of ferric iron in sections, Perls' method was combined with hematoxylin and eosin as follows. Deparaffinized sections of formalin-fixed tissues are stained in Perls' reagent (1:1 2%, w/v, of potassium ferrocyanide in distilled water and 2%, v/v, concentrated HCl in distilled water) for 20 min. After brief rinsing in distilled water stain sections in Mayer's hemalum, wash in tap water for 5 min, counterstain in 0.5% (w/v) eosin B in 50% ethyl alcohol for 15 sec. Rinse in tap water, dehydrate and mount as usual.     

The estimation of Wright's fixation index from genotypic frequencies

For populations in which the genotypic frequencies are estimated, it is customary to test the deviation of the estimates from those predicted by the Hardy-Weinberg Law using the x² goodness-of-fit statistic. Maximum likelihood estimation ofWright's F statistic and its variance furnishes a similar test. Following the derivation of the variance of , this note reviews the relation between the two tests. The F statistic possesses the advantages of full sufficiency and an easier formulation of the power function. Its bias is negligible when sample size exceeds 20.     

Simultaneous Demonstration of Connective Tissue elastica and Fibrin by a Combined Verhoeff's Elastic-Martius-Scarlet-Blue Trichrome Stain

A method for the routine combined demonstration of elastica, connective tissue in general, and fibrin is described. Elastica, stained blue-black by Verhoeff's iron hematoxylin, is contrasted with muscle and collagen, stained red and blue or green respectively, by a modification of the Martius-scarlet-blue (MSB) trichrome for fibrin of Lendrum et al. The MSB technique selectively stains fresh, mature and old fibrin orange-yellow, red and blue respectively; the Masson trichrome does not distinguish between erythrocytes and fibrin. Nuclei are stained at the same time as the elastica. The technique takes approximately one and a half hours and is ideal for the study of connective tissue and vascular pathology, especially the necrotizing vasculitides.     

The hypercycle,traveling waves,and Wright's equation

A formal relation between the hypercycle equation and the delay differential equation of E. M. Wright is exhibited using a traveling waves approach. Several unsolved questions in either problem can be related and interpreted, in particular new motivation for the study of Wright's equation is obtained.