Bio-Rad Mini-PROTEAN® TGX™ Precast Gels for 2-D Electrophoresis - Manual (Page 18)

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Native PAGE
4
4.1 Introduction
In native PAGE, proteins are prepared in nonreducing, nondenaturing sample buffer, which maintains
native structure and mass-to-charge ratios. Separation is also performed in the absence of SDS and
reducing agents. Though native PAGE uses the same moving boundary described for SDS-PAGE
(see Section 3.1), protein mobility depends on a number of factors other than molecular weight,
including the shape and charge of the protein. Protein-protein interactions may be retained during native
PAGE, so some proteins may separate as multisubunit complexes. Consequently, native PAGE is not
suitable for molecular weight determination.
The nonreducing and nondenaturing environment of native PAGE allows protein separation with
retention of biological activity. Because native structure is retained, native PAGE can enable separation
of proteins with the same molecular weight.
4.2 Mini-PROTEAN ® TGX ™ and
Mini-PROTEAN ® TGX Stain-Free ™ Gels
Mini-PROTEAN TGX gels are Laemmli-like gels that have a proprietary modification that extends their
shelf life to 12 months and enhances separation characteristics relative to conventional gel types. They
are run using standard native sample buffer and Tris/glycine running buffer, and they generate protein
migration patterns that are similar to those observed with standard Laemmli Tris-HCl gels.
Two types of TGX formulations are available:
n
Mini-PROTEAN TGX — Laemmli-like, extended shelf life gels
n
Mini-PROTEAN TGX Stain-Free — Laemmli-like, extended shelf life gels with trihalo
compounds that allow rapid fluorescent detection of proteins with the stain-free system,
eliminating staining and destaining steps for faster results (see Chapter 5 for more details)
These gels are available in a selection of polyacrylamide single percentages and gradients, and because
they contain no SDS, they can be used for either SDS- or native PAGE applications.
Gel Composition
Crosslinker 2.6% C
Stacking gel 4% T, 2.6% C
Shelf life ~12 months at 2–8°C; expiration date is printed on the packaging