Bio-Rad Prestained SDS-PAGE Standards - Manual (Page 3)

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 molecu-
lar weight determination, use Bio-Rad’s SDS-
PAGE, Silver Stain SDS-PAGE, or Biotinylated
SDS-PAGE Standards in addition to the
prestained standards.
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.
3 4
5 6
Instructions for Use
Heat the solution to 40 °C for 1 minute
to dissolve any solids which may have pre-
cipitated at -20 °C. To visualize the
prestained standards after blotting, load 10
µl 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 µl for mini gels. To see the stan-
dards during the run, it is helpful to hold a
sheet of white paper behind the gel.
Note: The prestaining of the proteins sub-
stantially inhibits them from being further
stained with biotin/avidin systems, colloidal
gold, Coomassie
® R-250, or amido black. The
standards can be silver stained, but silver
staining will result in broad bands because of
the large amount of protein in the sample.
Fig. 1. Low Range Prestained SDS-PAGE Standards.
5 µl of the standards were run on a 12% SDS poly-acry-
lamide gel according to the method of Laemmli.
1 The
standards were run on the Mini-PROTEAN ® II cell and
electrophoretically transferred to nitrocellulose using
the Mini Trans-Blot
® cell.
Phosphorylase B
Bovine serum
albumin
Ovalbumin
Carbonic
anhydrase
Soybean trypsin
inhibitor
Lysozyme
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