Method 1. Phage were mixed with bacterial cells for 10 minutes. (Long enough for adsorption but too short for further infection progress.) 2. The mixture is diluted by 10,000 (Only those cells that bound phage in the initial incubation will contribute to the infected population; progeny phage produced from those infections will not find host cells to infect)
Method 1. Phage were mixed with bacterial cells for 10 minutes. (Long enough for adsorption but too short for further infection progress.) 2. The mixture is diluted by 10,000. (Only those cells that bound phage in the initial incubation will contribute to the infected population; progeny phage produced from those infections will not find host cells to infect.)
3 Incubate the dilution at intervals, a sample can be removed from the mixture and the number of free phage counted using a plaque assay
3. Incubate the dilution. At intervals, a sample can be removed from the mixture and the number of free phage counted using a plaque assay
Phage Crosses and Complementation Tests Mixed infection: a single g cell is infected with two oo phage particles at once
Phage Crosses and Complementation Tests Bacteriophage Mixed infection: a single cell is infected with two phage particles at once
Mixed infection(co-infection) 1. It allows one to perform phage crosses If two different mutants of the same phage co-infect a cell recombination can occur between the genomes. The frequency of this genetic exchange can be used to order genes on the genome
Mixed infection (co-infection) 1. It allows one to perform phage crosses. If two different mutants of the same phage co-infect a cell, recombination can occur between the genomes. The frequency of this genetic exchange can be used to order genes on the genome
2. It allows one to assign mutations to complementation groups If two different mutant phage co-infect the same cell and as a result each provides the function that the other was lacking, the two mutations must be in different genes(complementation groups). If not, the two mutations are likely located in the same gene
2. It allows one to assign mutations to complementation groups. If two different mutant phage co-infect the same cell and as a result each provides the function that the other was lacking, the two mutations must be in different genes (complementation groups). If not, the two mutations are likely located in the same gene