2 public questions tagged with this topic.
SDS-PAGE (Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis) is used to separate proteins based on their molecular weight.
Ref: NCERT Class 12 Biology Chapter 9: Biotechnology: Principles and Processes Processes - Isolation of DNA and Gel Electrophoresis
Sodium dodecyl sulfate polyacrylamide gel electrophoresis provides indispensable size-based separation before Western blotting. SDS is an anionic detergent binding at approximately 1.4 grams per gram of protein, masking intrinsic charge and unfolding polypeptides into rod-like structures. Inclusion of reducing agents like dithiothreitol cleaves disulfide bridges. Migration through polyacrylamide sieving matrix then depends solely on polypeptide length logarithmically. This allows precise molecular weight estimation and resolution of isoforms. Techniques such as RT-PCR amplify nucleic acids, electroporation introduces DNA into cells, and ELISA detects without size resolution, none replicate SDS-PAGE function.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
