Bio-Rad ReadyPrep™ Protein Extraction Kit (Membrane I) User Manual
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Section 1
Introduction
The ReadyPrep protein extraction kit (membrane I) is a
simple, rapid and reproducible method to prepare cellular
protein fractions highly enriched in membrane and
hydrophobic proteins. This kit is part of a group of related
kits from Bio-Rad developed to reduce sample complexity
in order to improve the chances of identifying low-
abundance proteins, such as membrane proteins, and to
simplify proteomic studies. The fractionation protocol can
be applied to a wide variety of biological samples and the
isolated proteins are suitable for 2-D gel analysis or other
applications such as SDS-PAGE and western blotting.
Unlike many procedures used to isolate membrane
proteins, this kit does not require the use of
ultracentrifugation nor the preparation of density gradients.
The kit is based on the separation of membrane proteins by
temperature-dependent phase partitioning using Triton
X-114 detergent (Bordier 1981, Santoni et al. 2000). The
sample is first mixed and homogenized in the membrane
protein extraction buffers. After a brief incubation at 37°C,
the sample is centrifuged, producing an upper aqueous
phase and a lower detergent-rich phase. Proteins that were
anchored to the membrane or proteins containing one or
two transmembrane domains are efficiently partitioned to
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