Trypsin is among other three key digestive proteinases –pepsin and chymotrypsin-

whereby their main role is to break down complex protein molecules in to their simple forms; the

amino acids (Lowe & Dean, 2013). For laboratory purpose trypsin is isolated from crude

pancreas extract.

Affinity chromatography is a molecular used in separation and purification of generally

all biomolecules with regards of its chemical structure and biological function (chromatography,

2010). Sepharose is maostly used matrix where immobilization of ligand molecules is done. The

ligand to be used should have high affinity to the substrate- have specific and reversible binding

sites and have chemically modifiable group.

SDS page is a chromatography technique that uses a detergent called SDS (Dean,

Johnson, & Middle, 2012).The role of SDS is to disrupt protein –protein interactions and

denaturing the molecule that leads to its complete unfolding. Moreover it renders same charge to

all proteins by binding all to all proteins giving them uniform charges. This is important in

electrophoresis whereby now separation is due to size that is inversely proportional to protein

size. Thus small molecules move faster compared to large molecules. Migration of the substrates

determines gel length…