MBIO 3470 Lecture Notes - Lecture 8: Citric Acid Cycle, Phenetics, Ribosomal Rna

• School: University of Manitoba
• Department: Microbiology
• Course: MBIO 3470
• Professor: Vladimir Yurkov

Document Summary

One strain in the group is selected as the reference organism. The radioactive ss-reference dna is incubated with filters containing bound dna at tm ssdna from the reference is also prepared in the radioactive form (15-30 degrees c) to allow hybridization to take place. After washing, the radioactivity retained on filter is counted directly related to hybridization. The amounts of radioactivity retained in homologous hybridization (reference and bound dna come from the same organism) is taken as 100% hybridization. Less radioactivity is retained in heterologous hybridization because of differences in sequences of the bound and reference dna. Heterologous hybridization is reported as a percentage of the homologous hybridization. The amount of heterologous hybridization is directly dependent upon the sequence similarity of bound and reference dna. In order for heterologous hybridization to take place, there must be at least 70-80% sequence similarity between the dnas: %sequence similarity is not the same as % hybridization.