Alcian blue pyridine variant--a superior alternative to alcian blue 8GX: staining performance and stability

We compared the staining performance, dye content, solubility, and visual absorption maximum of two batches of alcian blue pyridine variant and of five batches of alcian blue 8GX (C.I. 74240). Whenever possible, we also compared results to those obtained with the same dye batches produced at an earlier date to provide information concerning dye stability. Both alcian blue pyridine variant batches were of high dye content, stable, of satisfactory solubility, and performed well in both the routine Mowry mucin stain and in the critical electrolyte concentration (CEC) stain. Of the five alcian blue 8GX samples, some were also of appropriate dye content, were sufficiently stable, and gave good staining in the two procedures. Two batches, however, were unstable, and three batches were unsatisfactory in staining performance and solubility in the CEC stain. Consequently alcian blue pyridine variant is a superior substitute for alcian blue 8GX.

Human prostatic endocrine-paracrine (APUD) cells. Distributional analysis with a comparison of serotonin and neuron-specific enolase immunoreactivity and silver stains

Prostatic endocrine-paracrine (PEP) cells from the prostates of 25 radical cystectomy specimens were studied using serotonin and neuron-specific enolase immunocytochemistry and argyrophil and argentaffin silver stains. Three populations of PEP cells were identified as follows: (1) serotonin-positive only, (2) serotonin-positive and argyrophil-positive (the largest population), and (3) serotonin-positive, argyrophil-positive, and argentaffin-positive. Neuron-specific enolase immunoreactivity correlated closely with serotonin immunoreactivity. The entire PEP cell cytoplasm was serotonin and neuron-specific enolase immunoreactive, while the silver stains only stained the granulated cytoplasm. The PEP cells were present in all areas of all prostates with a surprisingly large number in the large periurethral ducts with somewhat fewer PEP cells in the prostatic urethra and smaller ducts and ductules. The peripheral acini generally contained the smallest number of PEP cells. Prostatic endocrine-paracrine cells were of the open (luminal extension), closed, and dendritic types.

Plastic-embedded human marrow biopsy specimens: improved histochemical methods

Improved methods for processing, sectioning, and staining plastic (glycol methacrylate)-embedded human marrow biopsy specimens were studied. Special stains, including naphthol AS-D-chloro-acetate esterase, PAS, reticulin, and iron, have been modified so that they are suitable for undecalcified, 2-microns-thick, plastic-embedded human marrow biopsy specimens. These adaptations permit plastic-embedded marrow specimens to be used for clinical diagnosis. Marrow biopsy specimens embedded in plastic were compared with biopsy specimens preserved by the conventional paraffin method. The plastic-embedded marrows provide better results from morphologic examination (enhancing diagnostic accuracy), permit assessment of bone as well as of marrow, and allow histochemical analysis to be performed.

Iron gallein elastic method---a substitute for Verhoeff's elastic tissue stain

A method for staining elastic fibers in formalin fixed, paraffin embedded sections is described. After deparaffinizing and dehydration, sections are stained for 30 minutes in a solution prepared by mixing equal parts of 1% gallein dissolved in ethylene glycol and absolute alcohol (1:4), and 1.16% aqueous ferric chloride in 1% hydrochloric acid. The sections are washed in water and then differentiated in 2% ferric chloride for 2 minutes. After washing in water, the sections are counterstained with a variant of Van Gieson's picric acid-acid fuchsin for 1 minute. The results are similar to Verhoeff's elastic stain with elastic fibers staining black. An advantage to this staining procedure is that visually controlled differentiation is not necessary.

Immunofluorescence counterstains

Counterstains in the direct and indirect immunofluorescence methods may be used to reduce or eliminate background nonspecific staining or autofluorescence and to increase cellular and tissue detail. The advantages and disadvantages of a number of such counterstains in terms of (a) elimination of background fluorescence, (b) blocking of specific staining, (c) cellular detail and (d) rapidity of fading are discussed, and a new method of counterstaining nuclei with methyl green is presented. Methyl green counterstain is the procedure of choice when maximal cellular and tissue detail is desired. The lissamine-rhodamine-conjugated bovine serum albumin and eriochrome black methods are especially useful in reducing or eliminating nonspecific staining and tissue autofluorescence.