The Protein Man's Blog | A Discussion of Protein Research

Gene cloning is one of the most important steps in recombinant DNA Technology. Now-a- days researchers are using different cloning techniques depending on purpose, time, cost, ease of use and availability of resources.  A few of the techniques are briefly explained below.

Recombinant proteins are useful for studying biological processes and the structure of protein. Selecting an appropriate expression system is a crucial factor to produce correctly folded protein. Factors to consider when choosing an expression system include:

Biotinylation, also known as biotin tagging/labeling, is the process of attaching biotin to a protein molecule and other macromolecules. Considering its high affinity to avidin and streptavidin (with a dissociation constant of around 10 ^-15 M, biotin-avidin/streptavidin interaction is one of the strongest non-covalent interactions existing in nature), its high specificity and fast on-rate, this technique is perfectly suited for isolating and purifying proteins and protein complexes, as well as identifying protein-protein interactions and post-translational events.  

Affinity purification, also called affinity chromatography, is a laboratory technique used for purifying protein or protein complexes within a biochemical mixture. Unlike other chromatography-based purification methods which separate molecules based on size (i.e., gel filtration or size-exclusion chromatography) or strength of ionic interaction with a solid phase material (i.e., ion exchange chromatography), affinity purification works by manipulating certain molecular properties and specific binding interactions between molecules to purify the protein of interest.