User Manual

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Peptide Analysis
6
6.1 Introduction
Criterion
™
Tris-Tricine/peptide gels are optimized for separating peptides and proteins with molecular
weight <10,000. Peptide-SDS complexes move more slowly through these gels, allowing the faster SDS
micelles that normally interfere with peptide separations to separate completely from peptides. This
enables resolution of distinct peptide bands.
6.2 Criterion Tris-Tricine/Peptide Gels
6.2.1 Gel Composition
Gel buffer 1.0 M Tris-HCl, pH 8.45
Crosslinker 2.6% C
Stacking gel 4% T, 2.6% C
Storage buffer 1.0 M Tris-HCl, pH 8.45
Shelf life ~12 weeks at 2–8°C; expiration date is printed on each cassette
6.2.2 Gel Selection Guide
Criterion Tris-Tricine/peptide gels are available in either a single percentage or a linear gradient format.
Gel Percentage Optimum Separation Range
16.5% 1.5–30 kD
10–20% 1–40 kD
6.3 Tris-Tricine/Peptide Buffers
See Appendix B for buffer formulations. Do not adjust pH unless instructed to do so.
Running buffer (1x) 100 mM Tris, 100 mM Tricine, 0.1% SDS
Dilute 100 ml 10x stock (catalog #161-0744) with 900 ml diH
2
O
Sample buffer 200 mM Tris-HCl, pH 6.8, 2% SDS, 40% glycerol, 0.04% Coomassie
(catalog #161-0739) Brilliant Blue G-250, 2% β-mercaptoethanol or 100 mM DTT (added fresh)