title: Determination of correction factors of 3H-beta-self-absorption for quantitative evaluation of grain number in autoradiographic studies. Interferometric studies of different cell types in the mouse brain.
abstract: Deparaffinized and Feulgen-stained sagittal sections of the mouse brain were studied interferometrically in order to measure optical path differences of euchromatin and heterochromatin of various cell types. Furthermore, the ratio eu-: heterochromatin of each cell type was determined. From these data mass densities of karyoplasm and, finally, correction factors of 3H-beta-self-absorption were calculated for comparing grain numbers of different cell types in quantitative autoradiographic studies after application of tritium-labelled substances. Remarkable differences of correction factors up to a factor of 2.18 were found. Furthermore, the actual section thickness was determined interferometrically. A reduction to about 0.60 of the microtome setting was measured in two different areas of the brain. Using mass densities together with actual section thickness correction factors for a thickness of 1 micron were calculated. This was done also for cell types outside the brain the data of which were taken from literature. Thus, differences in correction factors up to about a factor of 4 were found pointing out the importance of considering 3H-beta-self-absorption in quantitative autoradiographic studies.
mesh_terms: D000818:Animals; D001345:Autoradiography / Q000379:methods*; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D004396:Coloring Agents; D004727:Endothelium / Q000378:metabolism; D022041:Euchromatin; D006570:Heterochromatin / Q000378:metabolism; D007368:Interferometry; D008297:Male; D051379:Mice; D009457:Neuroglia / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D011689:Purkinje Cells / Q000378:metabolism; D012394:Rosaniline Dyes; D014316:Tritium / Q000378:metabolism*
chemical_list: D002843:Chromatin; D004396:Coloring Agents; D022041:Euchromatin; C007722:Feulgen stain; D006570:Heterochromatin; D012394:Rosaniline Dyes; D014316:Tritium