Tag Archives: lab

DNA methylation systems

By | July 9, 2021

The E. coli strains used in the laboratory for cloning and DNA isolation contain three site-specific DNA methylation systems. Modification of DNA using these methylation systems protects the potential restriction enzyme recognition sites from cleavage. This genetic engineering technique sheds light on the sensitivity of restrictions endonuclease towards DNA methylation. Such DNA methylation systems are:… Read More »

Quantitative/Real-time PCR (Polymerase Chain Reaction)

By | July 6, 2021

PCR (Polymerase Chain Reaction): The two strands of the target DNA molecule are denatured and separated by heating (94 degrees Celsius), in the first step of PCR. In the second step of PCR, annealing, unique sequences around 20 bp (oligonucleotides) complementary to 5′ and 3′ part of the target DNA called primers will bind. The… Read More »

How to design primers for PCR (Polymerase Chain Reaction)?

By | June 30, 2021

Primers will have the following characteristics: Primers will have a sequence length of 17 to 30 nucleotides. This enables unique annealing of the primer to a single sequence of the genome. Their GC content will be at least 50 percent. There should be more GC content towards the 3′ end so that it’s bound strongly… Read More »