Screening for Cloned Inserts

Quick and Dirty Screening for Cloned Inserts

For identifying positive clones from a plasmid cloning procedure, the routine of performing a mini-prep and then checking the putative clones by restriction digestion is most commonly used. Of course, if you need to screen a large number of clones, another option is a colony PCR to identify positives, followed by restriction digests to confirm….

The Invention of PCR

Few technical breakthroughs have changed the face of their field like the Polymerase Chain Reaction (PCR). Gene cloning, sequencing of complex genomes, DNA fingerprinting and DNA-based diagnostics are just some of the techniques that were either inefficient, crude or plain impossible before PCR. The technique has revolutionized biological research and biotechnology to such an extent…

Competent E.coli: To buy or not to buy?

Competent E.coli: To buy or not to buy?

Buying competent cells from commercial suppliers is convenient, provides a guarantee of quality, and gives access to strains with a variety of in-built traits that assist with things like maintenance of plasmid integrity (more on these traits later). However, this can be an expensive business. Alternatively, competent cells of any strain, including the specially-constructed commercial…

Easier Gene Cloning With Positive Selection Cloning Vectors

Easier Gene Cloning With Positive Selection Cloning Vectors

Isn’t it a pain digesting, purifying and dephosphorylating your cloning vector prep to eliminate prevent high background in your ligation/transformation? A new generation of positive selection cloning vectors promises to eliminate all of that hassle by killing off any vector that has not taken up the insert you are trying to clone. Positive selection cloning…

Custom Gene Synthesis: A PCR alternative.

Artificial gene synthesis was first reported in 1972 when a group of researchers at Massachusetts Institute of Technology synthesized a complete yeast alanine tRNA gene. Synthesis of the first peptide- and protein-encoding genes ensued in the following decade. Since then, synthetic biology has advanced in leaps and bounds, and custom gene synthesis, a one-time expensive option for…