Owner's manual

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4.5 Running Conditions
We recommend running SDS-PAGE gels in the Model 491 prep cell using 12 W constant power. Values for
voltage and current should correspond to the settings listed in Table 4. Different running conditions apply for
native-PAGE (Section 9).
Table 4. Running conditions for preparative SDS-PAGE.
12 W Constant Power
Small gel tube (28 mm ID) 40–50 mA/240–300 V
Large gel tube (37 mm ID) 50–60 mA/200–400 V
4.6 Elution Times for Proteins
Elution times for proteins run through SDS-PAGE gels at 12 W constant power are estimated in Table 5. When
SDS-PAGE is carried out at the optimum %T, the relative mobility (Rf) for the protein of interest will be about
0.55–0.6. This corresponds to a velocity of ap proxi mately half that of the ion front, regardless of the size of the
pro teins. Therefore, the elution times for preparative SDS-PAGE are af fected by gel length and gel tube size
only and can be predicted. The elution times for both the ion/dye front and the puri fied protein are pro vided in
Table 5.
Table 5. Elution times at optimal %T.
Gel Length ,cm Elution Time for Proteins
(Rf~0.55), hr
Elution Time for Ion Front
(Rf=1), hr
28 mm gel tube
5 3.5 2.0
6 4.5 2.25
7 5.25 2.75
8 5.75 3.0
9 6.5 3.5
10 7.25 3.75
37 mm gel tube
5 6.0 3.0
6 6.75 3.5
7 7.75 4.0
8 8.5 4.5
9 10.0 5.25
10 11.0 5.5
*The elution times are approx imate and will vary somewhat depending on the exact run conditions.
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