Chemistry
How SDS-PAGE Separates Proteins by Molecular Weight
Quick fact
SDS denatures proteins and gives every protein roughly the same negative charge per unit mass, so the only difference in how they move through the gel is their size.
Why this is interesting
Imagine being able to separate a mixture of proteins into neat bands, each one marking a different size. That’s exactly what SDS-PAGE does—but how does it make proteins move solely by their weight?