BIO370Y5 Lecture Notes - Lecture 8: Repressor, Dna Replication, Escherichia Coli
Document Summary
Lab 8- virology: analysis of bacteriophage mutants and phage particle counts (plaque assays) 100 or more progeny particles are produced in one sensitive bacterium. Bacteria grow a lawn of cells on agar. When you add phage to this, they create plaques (areas where theres no bacteria cause its dead: # of plaques = # of viruses, repped as pfu/ml (pfl= plaque forming units) Phage solutions usually have 108 1011 pfu/ml but to get here we must dilute. Can also help with distinguishing phage genotypes, since it shows us different plaques. Indicator strain: the bacteria we use in plaque assays. Each group has a bacteriophage and its approx. concentration. Amber mutation in the p gene (pam80) is necessary for phage dna replication. Cl857 is the repressor gene cl and is also temperature sensitive: a mutation causes phage to grow lytically. Ts allele of cl is a classic allele cl857 (called clts)
