Bio-Rad Mini-PROTEAN® Tetra Handcast Systems - Manual (Page 8)

d. Add the initiators to the heavy solution, swirl it 8 to 10 times, and pour it into the
reservoir chamber (which is labeled "heavy"). Start the stir plate and adjust the speed so
that you get good mixing; the bottom level of the vortex should be nearly the same as the
acrylamide level in the resevoir chamber.
e. Quickly open the valve stem and stopcock. The acrylamide will flow through the tubing
and needle to the gel sandwich. Do not allow air bubbles to enter the gel. Overlay the
acrylamide with water or water-saturated isobutanol. For a continuous buffer system, insert
a comb. (The comb should be inserted at an angle to prevent the formation of bubbles.)
f. Remove the tubing and disassemble the gradient former. Immediately flush the system
with water to prevent polymerization of residual acrylamide within the gradient former.
Section 4
Gradient Former Care and Maintenance
After use, disassemble the gradient former and rinse all parts with distilled water. If the
gel polymerizes in the gradient former during casting or before the system can be flushed
with water, remove the valve stem and stopcock and rinse thoroughly. The needle can be
replaced (catalog number 165-2007). A Tubing Connection Kit (catalog number 165-2008)
includes replacement Tygon tubing, a luer fitting, stopcock, and a Y connector. Do not use
organic solvents, strong acid solutions or ethanol in the gradient former.
Section 5
Product Information
Catalog
Number
Description
165-4120 Model 485 Gradient Former
165-2006 Exponential Piston
165-2007 Gradient Pouring Needles , 2
165-2008 Tubing Connection Kit , includes stopcock, tapered luer coupling,
tubing (1/8 inch ID, 3 feet), and Y-connector
Appendix A
Estimated Volume of Acrylamide for
12 Mini-PROTEAN 3 Gels
The first time gels of a certain thickness are cast, it is necessary to empirically determine
the required volume of acrylamide. Assemble the stack, and inject a measured volume of
water through the stopcock. Prepare this volume (+5 ml) of acrylamide.
As a guideline, this is the estimated volume of acrylamide for 12 Mini-PROTEAN 3 gels:
Spacer plates Volume for 12 gels Volume to prepare
0.5 mm 70 ml 75–80 ml
0.75 mm 80 ml 85–90 ml
1.0 mm 100 ml 105–110 ml
1.5 mm 140 ml 145–150 ml
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