[Cytospectrophotometric analysis in enzyme histochemistry (limits of reproducibility and reliability)]

The article discusses results of the investigation into variability of the thickness of sections of a non-fixed frozen tissue obtained in cryostat, the dependence of optic density of histoenzymological preparations upon the thickness of a section and duration of incubation, degree of the accuracy of measurements of the optic density by probes of a different diameter, compatibility of results obtained by various techniques of cytospectrophotometry. It is shown that when the scale of microtome-cryostat was set at 5 mcm the thickness of sections varied in the range of 10%, at 10 mcm--in the range of 2%. In preparations as thick as 10 mcm2 and more lineal interrelationships between their optic density and duration of incubation were observed. In the photometric analysis of results of tetrasole reactions the accuracy of measurement is inversely proportional to the size of the probe: M+/-m--0.27+/-0.006--0.009 with area 3.0 mcm2 and 0.27+/-0.002 fith aea 0.8 mcm2. Results of measurement of optic density of ethanol by photoelectric and photographic techniques of cytospectrophometry (on the apparatus MUF-5, MUF-6, MF-2, MF-4, IFO-451) differ in the range of 0.5%, of histoenzymalogical preparations--in the range of 5--7%. On the basis of the data obtained a conclusion may be drawn that, if certain conditions are observed, the cytospectrophotometric analysis of histoenzymological preparations will give compatible results the accuracy of which meets the requirements put in a 95% level of probability.