Protein Gel Electrophoresis (SDS-PAGE)

Definition

SDS-PAGE (Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis) is a technique used by biologists to separate proteins according to their size.

Analogy

Imagine protein gel electrophoresis as a race where all runners (proteins) start at the same point but finish at different times because they run at different speeds. The smallest runner (protein) will reach the finish line first because they can move through the crowd more easily.

Related terms

Western Blotting: A technique that uses antibodies specific for a protein of interest after SDS-PAGE separation, allowing for detection and quantification of that protein.

Molecular Weight Marker/ Ladder: These are mixtures of proteins with known sizes which are run alongside samples in SDS-PAGE so we can estimate the size of our sample proteins by comparing them to the marker bands.

Polyacrylamide Gel: The medium used in SDS-PAGE, which acts like a sieve, allowing smaller proteins to move faster than larger ones.