Hoefer SE640 - Manual (Page 21)

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Gradient gels
Both linear and exponential gradient gels can
be poured in the dual gel caster. We recommend
using a Hoefer SG Series Gradient Maker. Gra-
dient gels are poured with a cannula from the
top of the dual gel caster (see Fig 5). A stacking
gel is then poured over the gradient gel.
Pouring a linear gradient gel
1
Assemble sandwich(es) into the dual gel caster as
described on page 8.
2
Set up the monomer solution flow path
Run a length of Tygon ™ tubing through a peristaltic
pump. Attach one end of the tubing to the gradient
maker outlet port and the other end to a 9 cm
cannula. (The OD of the cannula must be less than
the spacer thickness.) Place the cannula so that it
rests at the bottom of the sandwich, midway between
the spacers.
3
Prepare the monomer solution
Calculate the volume of monomer solution needed.
Divide the total volume in half and prepare this
volume of both the higher- and lower-percentage
acrylamide solutions.
Fig 5. Pouring a gradient gel.
The gel solution may be intro-
duced into the gel sandwich
through a pipette tip at a rate that
maintains a continuous stream.
Optional: Adjust the higher-
percentage acrylamide solution
to 15% (w/v) sucrose or
25% (v/v) glycerol to improve
layering.