Protein Sample Buffer (5X) is used to prepare protein samples prior to SDS-PAGE.
It can protect proteins from heat degradation during the sample preparation step, as well against pH changes during the SDS-PAGE electrophoresis.

Components:
5X Protein Sample Buffer 25mL x 1
+ 2-mercaptoethanol 1.25mL x 1

Composition of Protein Sample Buffer (5X):
0.3M Tris-HCl (pH6.8)
50% Glycerol
10% SDS
0.5% NaN₃
0.05% Bromophenol Blue

INSTRUCTIONS:

1. Proportionally add 2-mercaptoethanol into 5X Sample Buffer before use. The suggested ratio is 5%.
2. Mix sample with prepared 5X Protein Sample Buffer at the ratio 4:1.