Bio-Rad Precision Plus Protein™ Prestained Standards User Manual
Page 3
Lo
g M
W
r
2
= 0.996
0 0.5 1.0
3
2
1
0
Relative front
Instructions for Use
Precision Plus Protein Kaleidoscope standards
are provided in loading buffer, ready to load,
with no dilution required. Allow the tube to reach
room temperature and thoroughly mix before
use. This will ensure that any solids that may
have precipitated have returned to solution. Do
not heat the product above room temperature.
Recommended Loading Volumes
Load Volume
Application
5 μl
Blotting mini (8.3 W x 6.4 L cm) and midi
(13.3 W x 8.7 L cm) gels, monitoring transfer
10 μl
Mini and midi gel electrophoresis
20 μl
Large (18.3 W x 19.3 L cm) gel electrophoresis
Specifications
Catalog #
161-0375, single unit
161-0395, 5-pack value pack
Volume
500 μl
Number of
50, single unit
applications
250, 5-pack value pack
Loading
30% (w/v) glycerol, 2% SDS, 62.5 mM Tris,
buffer
pH 6.8, 50 mM DTT, 5 mM EDTA, 0.02% NaN
3
,
0.01% bromophenol blue
Shelf life
12 months at –20°C; if the product has been
stored as directed for longer than 12 months,
the shelf life may be extended by adding
dithiothreitol (DTT) to 50 mM
Total protein
1.5 mg/ml
concentration
Fig. 1. r
2
plot for Precision Plus Protein Kaleidoscope
standards determined on a Criterion 4–20% gel.
r
2
values
>0.99 are typical for Precision Plus Protein Kaleidoscope standards.
Product Description
Precision Plus Protein Kaleidoscope standards
contain ten protein bands of 10, 15, 20, 25, 37,
50, 75, 100, 150, and 250 kD.
Recombinant prestained protein standards are
carefully engineered for precise and accurate
molecular weights. The staining process has been
optimized to guarantee the same electrophoretic
molecular weight with each lot. Traditional
prestained proteins, on the other hand, are
blended from naturally occurring proteins. They
have an inherent variability in the amount and
location of dye that covalently binds to the protein;
this produces diffuse, broader bands than those
of the recombinant prestained standards and the
resulting molecular weights vary from lot to lot.
Molecular Weight Estimation
The molecular weights of Precision Plus Protein
Kaleidoscope standards are confirmed by
migration in a Laemmli SDS-PAGE system.
Using Precision Plus Protein Kaleidoscope
standards, the molecular weight of an unknown
protein can be assessed at an accuracy of 95%.
For electrophoretic determination of molecular
weights at an accuracy of >95%, Precision Plus
Protein Unstained standards (catalog #161-0363)
should be used.
These standards are also compatible with the
XT buffer system, but should only be used for
molecular weight estimation. For molecular weight
determination on XT gels, use the Precision Plus
Protein Unstained or All Blue standards.