Affinity chromatography is a versatile separation protocol that uses the biological interactions for characterization and detailed analysis of sample components. It is based on highly specific interactions between two molecules, such as the interactions between enzyme and its substrate, receptor, and ligand, or antibody and antigen. These reversible interactions are…

Developed by Marion M. Bradford in 1976, the Bradford assay is quick protocol, and the same amount of proteins are used as the Lowry assay. This assay is somewhat accurate, and out of range samples can be retested within minutes. This assay is recommended for general use, especially for assessing…

Fast protein liquid chromatography (FPLC) is a type of liquid chromatography that provides high resolution by small-diameter stationary phases for protein characterization and separation. The technique features high loading capacity, biocompatible buffer systems, fast flow rates, and stationary phases for common chromatography modes (e.g., gel filtration, ion exchange, reversed phase,…

Gel-filtration chromatography, also known as the size exclusion chromatography, is a versatile technique that permits the separation of proteins and other biological molecules. The gel filtration chromatography separates the proteins solely based on molecular size differences. For this, a porous matrix is used to which the molecules, for steric reasons,…

Ion Exchange Chromatography (IEC) is a powerful liquid chromatographic technique used for bioseparation. The separation is done by a reversible interaction between charged molecules of the sample with charged ligands attached to a column. The method offers a sizeable sample-handling capacity, powerful resolving ability, broad applicability, moderate cost, and the…

High-performance liquid chromatography (HPLC) is a powerful separation technique used for the analysis of ions, proteins, and organic molecules. HPLC is based on the mechanisms of adsorption, partition and ion exchange, which depend on the type of stationary phase used. The technique involves a solid stationary phase, usually enclosed in…

The Kjeldahl method was developed by a brewer called Johann Kjeldahl in 1883. The protocol is built on the principle that strong acid helps in the digestion of food so that it releases nitrogen which can be determined by a suitable titration technique. By observing the nitrogen concentration of the…

The estimation of proteins via the quantitative method is one of the basic requirements in biochemistry. Proteins, from various perspectives, are substantially more complex than nucleic acids. Thus, it has been hard to give laboratory protocols that can be applied to proteins. The precise quantitation of the amount of protein…