C.B.S. Scientific DGGEK-4801 - Manual (Page 10)

18 19 www.cbsscientific.com Cipher DGGE Instructions 2/28/14
3 2 Gel Casting Techniques- continued
B. Vertical gradient gel casting using GM-40 gradient maker and gravity flow.
1. Place the GM-40, gradient maker, on an elevated magnetic stirrer with a small
“flea” stir bar in the cylinder (C-2) closest to the outlet. The gradient maker
should be fitted with a leur valve, (V-2) and a 20ga needle with attached tubing
to deliver acrylamide to the gel plate sandwich as shown in figure (3.5). With
the height differential between the leur valve (V-2) and the top of the gel plate
sandwich between 2-4 inches, it takes approximately 5-9 minutes to cast the
gel. Raising the height of the gradient maker can increase flow rate. Flow can
be regulated by turning leur valve (V-2). Flow rate appropriate for each gradient
should be determined empirically.
Fig 3-5
3 2 Gel Casting Techniques- continued
C Vertical gradient gel casting using gradient maker (GM-40) and a mini-
pump
1. Alternatively, you may choose to use a “mini-pump” or other peristaltic
pump to cast gels as shown in fig (3.6). If so, secure the gradient maker to
a ring stand and connect the outlet tubing to the mini-pump tubing adapter.
Connect tubing from mini-pump to a 20ga. needle for affixing between glass
plates.
Fig 3-6
C-1
C-2
V-1
V-2