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In situ hybridization (ISH) allows for the histological and cytological localization of DNA and RNA targets. ISH has been useful as a research tool, and recent studies have used this technique in the diagnostic pathology laboratory and in microbiology for the tissue localization of infectious agents.However, the application of ISH techniques can be limited by their inability to detect targets with low copies of DNA and RNA. During the last few years, several strategies have been developed to improve the sensitivity of ISH by amplification of either target nucleic acid. sequences before ISH or signal detection after the hybridization is completed. Current approaches involving target amplification as in situ PCR, and signal amplification as tyramide deposition are reviewed with emphasis on their applications to bright field microscopy. Application of some of these techniques has extended the utility of ISH in diagnostic pathology and in research, because of the ability to detect targets with low cop...

Liver biopsies are some of the most commonly encountered specimens in any pathology laboratory, but yet are some of the most intriguing. Unlike medical renal biopsies, diagnoses in medical liver bi...

A routine pathology laboratory requires that selected tissue samples in a wide range of sizes from a vast array of organ systems be batch processed. This lack of homogeneity can lead to improper or overprocessing. The use of a softening agent following coarse trimming not only facilitated the cutting process but also provided improved microanatomical detail. Successive soaks in Horne's modified Baker solution (addition of phenol) and Mollifex (a commercial mixture of glycerin, phenol derivative, acetone, and alcohol) gave most satisfactory results. (The J Histotechnol 15:321, 1992)

Introduction It may come as a mild shock to the reader that this article will not advocate anything new and sensational. In order to put the topic into perspective one should analyze the reasons for which special stains any special stains in a hospital environment or the laboratory practice of pathology are carried out. Special stains are done: (1) in order to find certain features which would help make a tissue diagnosis and ultimately help the patient; (2) to confirm an impression that was already gained by routine HE (3) as an important teachingdemonstration tool; and (4) as a time delay to enable the pathologist to do more research on the subject. From past experience most special stains seem to be ordered by the younger, less experienced or less pragmatic pathologists. No laboratory should accept the request for special stains from the referring clinician. This occurs occasionally when specimens arrive with a request for "acid fast and fungus stains" or "amyloid stain." On scrutiny of the routine sections, there are no granulomata in which to look for organisms or dermal collagen and adnexae and vessel wall show no features that would warrant staining for amyloid. There is a certain mystique about "special" stains which should be dispelled. Dermatolvgists seem to be more prone to order or do special stains than are general or surgical pathologists. Some scientific publications show the description of a lesion with the results of a battery of special stains, none of which actually contribute anything to the understanding of that lesion. In the workload of the average hospital pathology laboratory, dermatopathology takes up a very small percentage of cases. There may be more skin lesions in the material of large reference laboratories or mail-in laboratories. Most of these, however, are rather trivial ones, like nevi and small basal cell carcinomas, etc.