Bio-Rad Criterion™ TBE-Urea Precast Gels - Manual (Page 31)

Nondenaturing Nucleic
Acid PAGE
9
9.1 Introduction
Criterion ™ TBE gels are used to separate small double-stranded DNA (dsDNA) fragments, particularly
PCR products. DNA molecules have nearly uniform mass-to-charge ratios, allowing nondenaturing
nucleic acid PAGE to separate dsDNA by mass using a continuous TBE buffer system.
9.2 Criterion TBE Gels
9.2.1 Gel Composition
Gel buffer
89 mM Tris, 89 mM boric acid, 2 mM EDTA, pH 8.3
Crosslinker 3.3% C
Stacking gel 4% T, 3.3% C
Storage buffer 89 mM Tris, 89 mM boric acid, 2 mM EDTA
Shelf life ~12 weeks at 2–8°C; expiration date is printed on each cassette
9.2.2 Gel Selection Guide
Gel Percentage Optimum Separation Range
5% 200–2,000 bp
10% 50–1,500 bp
15% 20–1,000 bp
4–20% 10–2,000 bp
9.3 Nondenaturing Nucleic Acid PAGE Buffers
See Appendix B for buffer formulations. Do not adjust pH unless directed to do so.
Running buffer (1x) 89 mM Tris, 89 mM boric acid, 2 mM EDTA
Dilute 100 ml 10x stock (catalog #161-0733) with 900 ml diH
2
O
Sample buffer (5x) 50 mM Tris-HCl, pH 8.0, 5 mM EDTA, 25% glycerol, 0.2% bromophenol
(catalog #161-0767) blue, 0.2% xylene cyanole FF
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