ZOO 3000 Lecture Notes - Lecture 1: Propylene Glycol, Complementary Dna, Sudan Iii
8 Feb 2018
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Document Summary
Discipline concerned with the localization and identification of chemical constituents in tissues. Historically started by botanist and microscopist, fran ois raspail (1794-1878), he stained for starch in plant cells using iodine. Classical text - lison"s "histochimie animale" (1936) Must often "preserve" the biological activity and structure of cellular constituents - how best to do this: Freeze substitution: ice replaced by organic solvent. If well preserved and fixed - possible to identify. Inorganics - ca, fe, ba, zn, pb, hg. Whatever component of interest, must run some kind of control. Widely distributed throughout tissue as glycogen and mucopolysaccharides (fig. Mechanism - periodic acid cleaves hexose sugars to yield aldehydes. Many chemicals may be pas-positive so controls are often run. Mild hydrolysis in 1n hci at varying temperatures for varying times ---> forms aldehydes in deoxyribose groups. Schiff"s reagent added and stains free aldehydes.
