Section 1
Introduction
Blotting was first performed by Southern
1
in 1975 with the transfer of DNA from agarose
gels to nitrocellulose membranes. Blotting has subsequently been applied to RNA
2-4
and
protein
5,6
from both agarose and polyacrylamide gels. Membrane materials have been expanded
to include PVDF for improved protein binding capacity. To overcome the inefficiency of
capillary transfers, electric current has been adopted for eluting proteins from polyacrylamide
gels, as first described by Towbin et al.
7
in 1979. Since that time, electrophoretic transfer has
also been used for DNA and RNA blotting.
8-14
For blotting PCR fragments, plasmid and vector DNA, and RNA with the SD cell, use the
Trans-Blot SD DNA blotting kit. DNA or RNA can be blotted from agarose gel to
Zeta-Probe
®
GT membrane in only 10 minutes, without any gel pretreatments. The kit comes
complete with DNA/RNA blotting accessories and a detailed instruction manual.
Semi-dry blotting was first reported by Kyhse-Andersen in 1984.
15
Blotting was
performed with plate electrodes in a horizontal configuration. The gel and nitrocellulose
membrane were sandwiched between sheets of buffer-soaked filter paper, which served as
the ion reservoir and replaced the buffer tank. The plate electrodes, separated only by the filter
paper stack, provided high field strength (V/cm) across the gel, and very efficient, rapid
transfers.
The Trans-Blot semi-dry transfer cell incorporates the original concepts of semi-dry
blotting along with innovative features for quick set-up and ease of use. The platinum-coated
titanium and stainless steel electrode pair provides efficient, background-free blotting with
trouble-free service.
1.1 Specifications
Construction
Trans-Blot SD body
Molded polycarbonate
Anode
Platinum-coated titanium
Cathode
Stainless steel
Anode platform
Precision machined acrylic
Overall size
37 cm x 24 cm x 11 cm
Maximum gel size
25 cm x 18.5 cm
Cleaning
Do not immerse the unit in liquid. Use special care
when cleaning the anode plate to avoid scratching
or marring the platinum. Do not use abrasives or
strong detergents. The cathode plate (stainless
steel) can be cleaned with a mild abrasive to
remove salt that may deposit during normal opera-
tion. The entire unit can also be periodically disas-
sembled and cleaned with water to remove salt
deposits.
Chemical compatibility
The semi-dry blotter components are not compati-
ble with chlorinated hydrocarbons (e.g., chloro-
form), aromatic hydrocarbons (e.g., toluene,
benzene), or acetone. Use of organic solvents
voids all warranties.
1
