The microtomist's vade-mecum : a handbook of the methods of microscopic anatomy / by Arthur Bolles Lee.

Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: The microtomist's vade-mecum : a handbook of the methods of microscopic anatomy / by Arthur Bolles Lee. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    wit]i liaBmatoxylin (the preparations are not favorable for staining with safranin or other coal-tar colours). 32. Chromo-formic Acid (Eabl, Morph. Jahrb., x, 1884, pp. 215, 216).—Four or five drops of concentrated formic acid are added to 200 c.c. of 0‘33 per cent, chromic acid solution. The mixture must be freshly prepared at the instant of u.sing. Fix for twelve to twenty-four hours, wash out with water, harden in alcohol, stain with hematoxylin or safranin. For the study of karyokinesis. This is acknowledged to be one of the very best reagents for the purpose. 33. Chromic Acid and Spirit.—A mixture of 2 parts of -^th per cent, chromic acid solution with 1 part of methylated spirit was much used by Klein in his investigations into the structure of cells and nuclei, and found to give better results than the ordinary reagents (including even osmic acid). Hcematoxylin was used for staining. The addition of alcohol to augmeht the penetrating power of chromic acid seems to be a step in the right direction, and it is matter for surprise that such mixtures are not more used. The alcohol should be added to the acid in aqueous solution, as if strong alcohol be added to crystals of chromic anhydride, a very violent reaction is set up. 34. Chromo-osmie Acid (Max Flesch, Arcli.f. mile. Anat., xvi, 1878, p. 300).—This mixture (osmium O'lO, chromic acid 0‘25, water lOO'O), origi- nally introduced for the preparation of the auditory organ of vertebrates, is of general application. It does not require to he kept in the dark. Objects may remain in it for twenty-four or thirty-six hours without risk of the osmic acid over-blackening them. Flemming found it to preserve nuclear figures well, hut the preparations are pale, and difficult to stain well. He finds that the action of the mixture is improved (for nuclear figures) by the addition of acetic, formic, or other acid. This addition brings out the figures more shaiqrly, and has the further adv.antage of allowing of a sharper stain with bsematoxylin, picro-carmine, or gentian violet. He recommends the following formula, which may be considered to have supei’seded Max Flesch’s. 35. Chromo-aceto-osmic Acid (Flkmmtng, first or weak formula, Zellsitbstanz, Kern und Zelltheilung, 1882, p. 381).—- Glacial acetic acid . . The best results (as regards faithfulness of fixation) are ob- Chromic acid . Osmic acid