Lambda Dna

Lambda Phage DNA, Non-methylated from Escherichia coli host strain GM119 (rm-,dam-,dcm-) has been used:

• to calibrate spectrophotometer (LKB) and HPLC (high performance liquid chromatography) method for determination of bacterial genomic DNA G+C content
• to amplify the λ; exonuclease gene by polymerase chain reaction (PCR)
• in DNase activities

Lambda Phage DNA, Methylated from Escherichia coli host strain W3110 is suitable for use as a substrate for restriction enzymes. It was used for immunoprecipitation in ChIP assays.

The DNA of bacteriophage lambda contains 48,502 nucleotide pairs forming a linear duplex. The 5′ ends of this DNA molecule have self-complementary single-stranded protrusions of 12 nucleotides that can anneal to form circles. Upon entry into the host cell, the DNA circularizes in the presence of DNA ligase. Many such circles are generated during the early lytic infection. At a later stage in replication, these individual circles/rings are converted to linear concatemers by a process called rolling-circle replication. The linear concatemers are cleaved during packaging to form monomeric chromosomal units by the enzyme DNA terminase.