Bio-Rad Gel Doc™ EZ System - Manual (Page 34)

Criterion Stain Free TM System | Criterion Stain Free Gels
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Native PAGE
Criterion Tris-HCl gels are made without SDS, allowing separation of proteins
in their native conformation. The nonreducing and nondenaturing environment
of Native PAGE allows the detection of biological activity and can improve
antibody detection. Native PAGE can also be used to resolve multiple protein
bands where molecular mass separation by SDS-PAGE would reveal only one.
Native PAGE uses the same discontinuous chloride and glycine ion fronts as
SDS-PAGE to form moving boundaries that stack and then separate
polypeptides by charge-to-mass ratio. Proteins are prepared in a
nonreducing, nondenaturing sample buffer that maintains the proteins’
secondary structure and native charge density. Native PAGE is not suitable for
accurate molecular weight determination due to the variability of charge-to-
mass ratio among different proteins.
Criterion Tris-HCI Composition
Criterion Tris-HCl Gel Separation Guide
Native PAGE separates by charge-to-mass ratio, making individual protein
migration protein dependent. Optimal Tris-HCl gel percentages will have to be
determined experimentally.
Gel buffer 0.375 M Tris-HCl, pH 8.6
Cross linker 2.6% C
Storage buffer 0.375 M Tris-HCl, pH 8.6
Stacking gel 4% T, 2.6% C
Shelf life ~12 weeks;
individual expiration date is printed on each cassette