BIOL240 Study Guide - Quiz Guide: Mycobacterium Tuberculosis, Gram Staining, Methylene Blue
3 Feb 2016
School
Department
Course
Professor
Document Summary
Unstained bacterial cells transparent difficult to see. A colour compound stain is used to increase the contrast b/w the specimen and background. Simple staining method: a single stain is used and all cells generally stain the same colour, regardless of type. Allow to distinguish bacterial cells by morphological types (cocci, rods, spirals vibrios) Dyes examples: methylene blue, basic fuchsin (red), crystal violet. 2 types of simple staining procedures: positive staining procedures basic cationic chromophore negatively charged on their outer surface produces a pronounced attraction b/w these cationic chromophores and the organism e. g. methylene blue, negative staining procedures. Three general shapes: rod (bacillus), round (coccus), and corkscrew or spiral other kinds: stalked forms (caulobacter), club-shaped (corynebacterium), comma-shaped (vibrio) Morphological variations due to age or composition of the culture media: coccus round. Most nonmotile singly (micrococcus) pairs (diplococcus) chains (streptococcus) groups of four (gaffkya) Most motile singly pairs (diplobacillus) chains (streptobacillus) produced by several different species: spirillium spiral.
