
Reference
1. Laemmli, U. K., Nature, 227, 680 (1970).
Ordering Information
Catalog
Number Product Description
Prestained Standards
161-0305 Prestained SDS-PAGE Standards, low range, 500µl
161-0309 Prestained SDS-PAGE Standards, high range, 500 µl
161-0318 Prestained SDS-PAGE Standards, broad range, 500 µl
161-0324 Kaleidoscope Prestained Standards, 500 µl
161-0325 Kaleidoscope Polypeptide Standards, 500 µl
Molecular Weight Standards
161-0304 SDS-PAGE Standards, low range, 200 µl
161-0303 SDS-PAGE Standards, high range, 200 µl
161-0317 SDS-PAGE Standards, broad range, 200 µl
161-0314 Silver Stain SDS-PAGE Standards, low range, 200 µl
161-0315 Silver Stain SDS-PAGE Standards, high range, 200 µl
161-0306 Biotinylated SDS-PAGE Standards, low range, 250 µl
161-0311 Biotinylated SDS-PAGE Standards, high range, 250 µl
161-0319 Biotinylated SDS-PAGE Standards, broad range, 250 µl
161-0326 Polypeptide SDS-PAGE Standards, 200 µl
Specialty Standards
161-0310 IEF Standards, pI range 4.45-9.6, 250 µl
161-0320 2-D SDS-PAGE Standards, 500 µl
Bio-Rad Laboratories, 2000 Alfred Nobel Dr., Hercules, CA 94547
4006024 Rev D
Prestained
SDS-PAGE Standards,
Low Range
Catalog Number
161-0305
Product shipped at room temperature.
Store at -20 °C upon arrival

Bio-Rad’s prestained standards are available
in high, low, and broad molecular weight
ranges. Blue dye has been covalently attached to
the standard proteins and will not be dissociated
by normal staining or destaining. The protein
mixtures are provided in a stable aqueous solution. No reconstitution or further dilution is
required before use.
Applications
Prestained SDS-PAGE Standards provide a
quick and easy way to assess the quality of an
electrophoretic transfer and act as a control in
repetitive blotting experiments. The visibility of
the standards makes it possible to monitor the
separation of proteins while electrophoresis is
in progress, even after the dye front has run off
the gel. The standards can also be used to locate
a protein for excision from an unstained preparative gel.
Specifications
Contents Approximately 625 µg total protein*
in 33% (v/v) glycerol, 3% SDS, 10
mM Tris pH 7.0, 10 mM DTT, 2 mM
EDTA, 0.01% NaN3.
Storage -20 °C
Shelf life 1 year at -20 °C
Volume 500 µl
Applications 25-100
per vial
* Total protein concentration is an approximation based
on the average concentrations of multiple lots. Actual
concentrations will vary.
Coomassie is a trademark of ICI.
21

Protein Molecular Weights
The molecular weights of every lot of
prestained standards are individually calibrated
against Bio-Rad’s SDS-PAGE Standards. The
lot specific calibrated molecular weights are
included with every vial. Prestained standards
are useful for estimating the molecular weights
of sample proteins, however, for precise molecular weight determination, use Bio-Rad’s SDSPAGE, Silver Stain SDS-PAGE, or Biotinylated
SDS-PAGE Standards in addition to the
prestained standards.
34
Instructions for Use
Heat the solution to 40 °C for 1 minute
to dissolve any solids which may have precipitated at -20 °C. To visualize the
prestained standards after blotting, load 10
µ l for full size gels (16-20 cm) and 5 µl for
mini gels. To visualize the standards during
electrophoresis, load 20 µ l for full length
gels and 10 µ l for mini gels. To see the standards during the run, it is helpful to hold a
sheet of white paper behind the gel.
Note: The prestaining of the proteins substantially inhibits them from being further
stained with biotin/avidin systems, colloidal
gold, Coomassie
standards can be silver stained, but silver
staining will result in broad bands because of
the large amount of protein in the sample.
®
R-250, or amido black. The
Constituent Proteins
(See enclosed insert for lot specific
calibrated molecular weights.)
Protein Source
Phosphorylase B Rabbit muscle
Bovine serum albumin Bovine plasma
Ovalbumin Chicken egg white
Carbonic anhydrase Bovine erythrocytes
Soybean trypisn inhibitor Soybean
Lysozyme Chicken egg white
† Covalently bound dye alters the molecular weight of the
proteins and produces relatively broad bands. The molecular
weights are calibrated from the center of each protein band.
Fig. 1. Low Range Prestained SDS-PAGE Standards.
5 µl of the standards were run on a 12% SDS poly-acrylamide gel according to the method of Laemmli.
standards were run on the Mini-PROTEAN
electrophoretically transferred to nitrocellulose using
the Mini Trans-Blot
®
cell.
†
Phosphorylase B
Bovine serum
albumin
Ovalbumin
Carbonic
anhydrase
Soybean trypsin
inhibitor
Lysozyme
®
II cell and
1
The
5 6