BIOLOGY 242 Study Guide - Midterm Guide: Congo Red, Fuchsine, Ethylene Oxide

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

Document Summary

Positive stain (basic): its positive charge sticks to the negative surface of the microbe and stains it: example: crystal violet or methylene blue. Negative stain (acidic): the negative charge repels the negative surface of the microbe and stains the background. Smear: putting the cells on a slide before staining. Fixation: to preserve the internal and external features of the microbe, it attaches cells to the slide and usually kills them (heat them) Simple stain: a procedure that stain whole cells regardless of cell type. Differential stain: procedures that stain whole cells but stain cells of different types differently: more than one type of dye used, separates bacteria into groups, example: gram stain and acid fast stain. Structural stains: used to emphasize a single structure of a microbial cell rather than staining the whole cell: multiple steps, difficult to perform, exa(cid:373)ple: ma(cid:374)eval"s capsule stai(cid:374), lieffso(cid:374)"s flagella stai(cid:374), a(cid:374)d schaeffer a(cid:374)d.