Microscopica acta最新文献

Some technical aspects of Papanicolaou staining are reviewed. The history of the technique is traced from Mallory's aniline blue technique through Masson's trichrome procedure to the techniques of Shorr. The histochemistry of the three Papanicolaou staining solutions (aluminum-"hematoxylin", OG and EA) is discussed. The structure of the aluminum-hematein chelate and its mode of action are considered. A tentative mechanism is proposed for the characteristic differential counterstaining produced by Papanicolaou techniques, i.e. orangeophilia vs cyanophilia. It is suggested that differential counterstaining occurs as a consequence of 1) differences in cytoplasmic density, 2) differences in the molecular size of the anionic dyes, and 3) the inhibitory effects of phosphotungstic acid on the binding of small dyes. The review considers some recent quantitative studies of Papanicolaou stained cells and outlines some modifications of Papanicolaou's procedures. The text concludes with a discussion of alternatives to the Papanicolaou technique.

A simple apparatus for the processing of biological specimens for electron microscopy is described. It comprises a fluid exchange chamber with associated reservoir. By carrying out all specimen processing from fixation to embedding in the exchange chamber and infiltrating the dehydrating and embedding mediums progressively, the handling and osmotic stresses associated with standard step processing are minimised.

Mercurochrome was applied to tissues and tissue sections in an attempt to examine structural components either in visible light, fluorescence or electron microscopy. Samples of bone marrow from rats were fixed in glutaraldehyde alone, embedded in Durcupan, and studied by using semi-thin and thin sections. After treatment with mercurochrome in acetone before embedding, the eosinophilic granules from leucocytes and chromatin masses showed electron opacity as well as a yellowish green fluorescence under excitation with violet-blue or blue light. An additional treatment of sections with an alkaline hydroalcoholic solution of the dye allowed to visualize these structures under bright-field illumination and to improve the contrast in the electron microscope. This method offers the possibility to examine specific cell components by using a compound which simultaneously possesses staining, fluorescence, and electron microscopic contrasting properties.

In modern ultramicrotomes the thermic advance system has been replaced by a mechanical one. Earlier, conventional DC-voltage motors were used, but recently the step motor has become popular. In connection with such motors, the application of digital control elements is facilitated, thus increasing precision significantly. A further step towards improving the precision of the advance system is the application of microprocessors as intelligent and interacting control elements. The microprocessor can not only take over the function sensors, the function of regulation. This paper describes a working concept whereby the advance system does not, as usual, work freely, but in connection with a sensor which measures the advance, and first after a positive data comparison over the microprocessor, allows the cutting movement. The concept is not limited to ultramicrotomes but can also be applied to mechanical rotation microtomes.

The staining patterns of a modified Papanicolaou staining method and of its components are compared with those from the common Papanicolaou method. The staining results are investigated by the CIE-DIN-standardized color analysis. The medical investigator is able to discriminate more colors than this cytophotometric method, but this method is superior in the exact determination of colors. For neither of the both Papanicolaou staining methods it is possible to indicate one or two wavelengths for cytophotometric measurement using narrow-band filters which allows an optimal automated separation of nuclei, cytoplasms and background of all cell types. Keeping to this usual color analyzing method there is a better evaluation of the common Papanicolaou staining patterns. More saturated colors in the cyanophilic cytoplasms with the Papanicolaou staining patterns and in the eosinophilic cytoplasms with the investigated modified Papanicolaou staining patterns would be desirable. Since the resulting color patterns are similar from both stains, the modified Papanicolaou method has to prefer if it proves to be more reproducible.

The DAPI (4',6-diamidino-2-phenylindole)-fluorochrome was used to demonstrate phagocytized Cryptococcus neoformans using the mouse peritoneal cavity technique. These yeast cells were chosen because they are large and their capsules exhibit a deep yellow fluorescence which contrasts very well with the blue fluorescent nuclei of the phagocytes (preferentially macrophages). In other words, DAPI stains both, acid mucopolysaccharides and nuclear DNA. The capacity of the phagocyte nuclei to surround or even enclose the yeast cells was the most remarkable result. Generally, the application of DAPI in these phagocytosis experiments provides valuable information rapidly, easily and specifically.

A new, simple and relatively inexpensive electronic digital position readout (DPRO) system which can be applied to the rapid localization and recovery of microscopic material is described. It is based upon a commercially available digital position readout system which is routinely utilized by industry for small machine tools and measuring equipment. This has been mounted onto the stage of various microscopic instrumentation to provide X and Y coordinates relative to an arbitrary reference point. The integration of small computers interfaced to scanning interferometric, microdensitometric and fluorescence microscopes were used to demonstrate the reliability, versatility and ease of application of this system to problems of multiparametric measurements and analysis of cultured cells. The system may be expanded and applied to clinical material to obtain automatized, multiparametric measurements of cells in haematology and clinical cytology.

This paper presents a method for labeling antibodies with fluorescein isothiocyanate (FITC) and additional with horseradish peroxidase (HPOD). With this double labelled antisera the fluorescence-serologic antibody technique (FAT) as well as the enzyme-serologic antibody technique (EAT) was done bit by bit for the same object. How the presented pictures demonstrate the result of both techniques, FAT and EAT, are the same with the described method. So, it is possible after fluorescence-microscopical exploitation through a following histochemical proof of the HPOD to get permanent preparations with the same biological result.