Electrophoresis: How to Read Results

Protein Purification with Dialysis Tubing

Protein Quantification (Bradford Assay)

Bradford assay is a rapid and accurate method to determine the concentration of protein. The assay is based on the observation that the absorbance maximum for an acidic solution of Coomassie Brilliant Blue G-250 shifts from 465 nm to 595 nm when binding to protein occurs. Both hydrophobic and ionic interactions stabilize the anionic form of the dye, causing a visible color change. Within the linear range of the assay (~5-25 mcg/ml), the more protein present, the more Coomassie binds.

Bradford Assay

Experiment using Bradford Assay to determine protein concentration. Follows a specific protocol but can be used to understand how to perform a Bradford Assay.

Electrophoretic separation of Proteins

Electrophoretic separation of Proteins

Quantitative estimation of aminoacids by Ninhydrin Method

Amino acids are known to be the building block of all proteins. Twenty different amino acids are commonly found in proteins. Amino acids comprises of a carboxyl group and an amino group bonded to the same carbon atom (the α carbon).They differ from each other in their side chains (R groups),which vary in structure, size, electric charge and solubility in water. Hence their detection, quantification and identification in any sample constitute important steps in the study of proteins.

Video Lecture : Protein Structure III

Protein Structure III