BIOLOGY 242 Midterm: Lab 12

• School: Bloomsburg University
• Department: Biological Allied Health Sci
• Course: BIOLOGY 242
• Professor: Kipe- Nolt

Document Summary

Acid fast staining was developed to assist the identification of bacteria belonging to the genera mycobacterium and nocardia. These orga(cid:374)is(cid:373)s are (cid:862)high g+c gra(cid:373)-positi(cid:448)e(cid:863) a(cid:374)d ha(cid:448)e a (cid:448)ery high lipid (cid:272)o(cid:374)te(cid:374)t. Outside of the peptidoglycan layer is an additional waxy layer containing of mycolic acids, which prevents binding and penetration of dyes. Ki(cid:374)you(cid:374)"s (cid:373)ethod of a(cid:272)id fast: uses deterge(cid:374)ts to dri(cid:448)e dye i(cid:374)to (cid:272)ells. Once stained these bacteria resist decolorization with acid-alcohol and are therefore referred to as acid-fast bacteria: the ascospores, sexual spores, of members of ascomycota also stain acid-past positive with this procedure. Procedure: prepare smears and air dry, smears usually contain clumps because mycobacteria are difficult to emulsify, so grind the smear using a second slide, heat fixation, flood s(cid:373)ears (cid:449)ith ki(cid:374)you(cid:374)"s car(cid:271)ol fu(cid:272)hsi(cid:374), let sit for fi(cid:448)e (cid:373)i(cid:374)utes. Ri(cid:374)se (cid:449)ith water: decolorize with acid-alcohol for 15-30 seconds.