Forming The Gradients; Repeated Use Of The Same Gradient - Biocomp GRADIENT MASTER 108 Operating Manual

For Quick Seal vertical rotor tubes, use an 18 Ga needle-tipped syringe to top off the light solution
and fill the nipple to keep air bubbles from entering the gradient during the run.
5. For open-top tubes, caps are then applied while tilting the tube slightly and aligning the cap's air
escape hole with the last air to leave the tube. The air hole's position is marked with a raised ridge on
the cap. To avoid leaks during insertion, keep the cap's axis parallel to the tube's axis . If the cap is
inserted at an angle, the seal is ineffective. The "extra bit" of light solution added earlier is displaced
into the central reservoir of the caps, eliminating all free air bubbles from the inside of the tube
(small adhered ones are not a problem). Since free-floating bubbles have a very deleterious effect on
gradient formation, their removal is imperative.
Remove excess solution from the reservoir before starting the run.
For the nipple-topped vertical rotor tubes, caps are not needed. Simply top up the light solution
liquid to fill the nipple.
6. At the end of a run, the long or short cap should be removed with a gentle twisting motion so that any
liquid remaining in the air outlet does not disturb the gradient.
7. MagnaBase holders are placed in the center of the plate.
Caution: with the large 1" tubes, an unbalanced tube arrangement in the holder will cause uneven
rotation due to gear "slop", so balance the holder with blank tubes as you would the centrifuge rotor
itself.
8. Once the tubes are capped, you are ready to use the Gradient Master.
D. FORMING THE GRADIENTS
1. As described in Section B above, recall the run from memory and press RUN
2. The plate will tilt to the angle of the first step, pause for 5 sec to allow the two solutions to settle and
begin rotation. The rest is automatic.
3. The FAST key doubles the tilting speed, but should not be used for gradients. When gradient
formation is complete, the plate will return to 0° and give a beep:
4. Remove the caps with an upward twisting motion and then balance the tubes before you add sample.
E. REPEATED USE OF THE SAME GRADIENT
1. A convenient feature is the ability to rerun a gradient with just two key strokes. These are the LAST
and RCNT functions. After levelling the unit on startup, press DONE:
05-50% S1/2 5:00/60.0/25
RUN DOWN UP
05-50% S1/2 5:00/60.0/25
FAST
05-50% S2/2 4:58/88.0/10
Gradient Done
GRADIENT MASTER108v5.22
GRAD
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EXIT
EXIT
EXIT
SYST