C.B.S. Scientific GM-2000 - Manual (Page 7)

C.B.S. œ Scientific Linear Gradient Maker 7
2. When using the 10ml, 20ml or 50ml chambers attach gradient maker to a ring stand support
and drop a small magnetic flea or spin-bar into chamber on the right hand side (‘B’). Ensure
both valves are closed. Set up magnetic stirrer.
3. Outlet # 1 should be fitted with luer type valve and needle with attached tubing to deliver
acrylamide mix to gel plate sandwich.
4. Pour solution ‘B’ into right side of gradient maker. Turn on magnetic stirrer so that it gently
mixes the solution.
5. Open inside (middle) valve #2 to allow air bubble to escape. Allow approximately 1ml of
solution ‘B’ to backflow into the left chamber. Remove with pipette and add back to right
chamber B.
6. Add solution ‘A’ to left chamber of gradient maker.
7. Open valve #2 and, then, outside valve #1 to the pump.
8. Turn on peristaltic pump to drive the gel mix into the gel plate sandwich. The flow rate should
allow the gel formation to be complete in 10-20 minutes.
9. Exit tube should be attached to near side of gel plate with tape.
10. When all of the gel mix has entered the gel plate sandwich, place the end of outlet tubing
from valve #1 into a beaker and flush the chambers and tubing with distilled water so that
acrylamide will not harden in the apparatus.
Note: If gel volume is not enough to fill sandwich, use 0% to “top-off” if using the back
side of the sawtooth comb for flat interface formation. If using water-saturated Butanol
for overlay, leave a 0.5cm void to create a flat interface.
Gel size
Spacers Volume required
16.5cm x 200mm (yellow) 0.75mm 20mls (10.5mls per chamber)
16.5cm x 200mm (red) 1.0mm 30mls (15.5mls per chamber)
16.5cm x 200mm (blue) 1.5mm 40mls (21.0mls per chamber)
When inserting the flat side of the sawtooth comb, be careful not to exceed 3/16” depth
(about half of the tooth length). Otherwise, you will find it difficult to load your sample as
there will not be enough “notch” left above the edge of the glass plate. Allow gel to
polymerize for 20-30 minutes.