Low Acrylamide Percentage for Target Protein Size (Western Blot (Bands at Wrong MW))

Question

Accepted Answer

Lower molecular weight proteins migrate excessively fast through the gel, resulting in poor resolution and bands appearing at the bottom of the membrane or running off entirely. Common causes: 1) Acrylamide concentration below optimal range for low molecular weight proteins, providing insufficient gel matrix density 2) Gel pore size too large for target protein (<30 kDa), allowing excessive migration speed 3) Incorrect gel recipe selection without considering protein molecular weight range Solutions: 1) Use 12-15% acrylamide gels for proteins in the 10-50 kDa range 2) Consult vendor gel recipe guides to match acrylamide percentage with target protein molecular weight 3) Increase acrylamide concentration in custom gel preparations according to validated protocols 4) Consider using gradient gels (4-20%) when analyzing samples with wide molecular weight ranges