This assay is used when working with phage vectors carrying the beta-gal gene. If the cloning event disrupts a normally functional copy of the gene in the vector the resulting plaques would appear clear in the assay. If the phages contain a functional beta-gal gene they will form blue rings around their plaques. Any strain which is not an overproducer of beta-gal will work as indicator host bacteria; a single chromosomal copy of the gene is not a problem. - [Read Assay for Phage Containing the Beta-galactosidase Gene]
This assay is used when working with phage vectors carrying the beta-galactosidase gene (often used for immunological screening). If the cloning event disrupts a normally functional copy of the gene in the vector the resulting plaques would appear clear in the assay. If the phages contain a functional beta-galactosidase gene they will form blue rings around their plaques. Any strain which is not an overproducer of beta- galactosidase will work as indicator host bacteria. - [Read Assay for Phage Containing the Beta-galactosidase Gene Protocol]
Phenol/chloroform DNA extraction, running a gel for DNA from Phages. Rob Phillips Group: Physical Biology of the Cell - [Read Phage Protocols - DNA Gels]
Phage are streaked onto a medium to obtain an independent isolate prior to preparing a new lysate. This is done to reduce the likelihood of working with lysates which have become contaminated, and/or have accumulated mutations. - [Read Streaking Lambda Phages Protocol]
Unlike spherical phage, such as T4 and λ, which have roughly equal weight ratios of protein to DNA, filamentous phage have about six times more protein than DNA; the protein therefore contributes substantially to the absorption spectrum.