HSS 1100 Lecture Notes - Lecture 3: Streaking, Microbiological Culture, Microorganism

• School: University of Ottawa
• Department: Health Sciences
• Course: HSS 1100
• Professor: Franco Pigatto

Document Summary

Diagnostic microbiology: isolation of pure culture from specimen, microorganisms in nature exist as mixed cultures and are therefore difficult to study. When enough cells have divided (~a few million), colonies are formed which are visible to the naked eye. Each colony is derived from a single cell and all cells within a colony are identical to each other. Different species have different colonial morphologies therefore can be used as mean of distinguishing different species in a mix culture. Preservation of pure cultures: why would we want to keep a copy of a bacteria we isolated from a patient, short term versus long-term o, liquid nitrogen (-195, freezers, lyophilization (freeze-drying) The gram stain (hans christian gram: flood slide with crystal (or gentian) violet. (wash with running tap water), flood with gram"s iodine. (wash with water), carefully decolourize with 95% ethanol. (wash with water).