Bio-Rad Mini-PROTEAN® Tetra Handcast Systems - Manual (Page 9)

Sample calculation: preparing twelve 1.0 mm 4–20% gradient gels:
Casting twelve 1.0 mm gels requires 100 ml; prepare 110 ml.
Divide the total volume by 2 to get the volume required for each chamber. (For this example,
make 55 ml for the light chamber and 55 ml for the heavy chamber.)
Solution Volume Calculations:
Light Solution (4%)
Acrylamide
30% stock solution
(30%) (X ml) = (4%) (55 ml)
X = 7.3 ml
Tris-Cl Buffer
1.5M Tris-Cl stock buffer pH 8.8
(1.5M) (X ml) = (.375M) (55 ml)
X = 13.8 ml
Water
(55 ml)–(7.3 ml + 13.8 ml) = X
X = 34 ml
APS
10% Stock solution
(500 µl) / (100 ml) = (X µl) / (55 ml)
X = 275 µl
TEMED
10% of the APS volume; (275 µl) / 10 = X
X = 27.5 µl
Heavy Solution (20%)
Acrylamide
30% Stock solution
(30%) (X ml) = (20%) (55 ml)
X = 36.7 ml
Tris-Cl Buffer
1.5M Tris-Cl Stock Buffer pH 8.8
(1.5M) (X ml) = (.375M) (55 ml)
X = 13.8 ml
Water
(55 ml)–(36.7 ml + 13.8 ml) = X
X = 4.5 ml
APS
(500 µl) / (100 ml) = ( X µl) / (55 ml)
X = 275 µl
TEMED
10% the APS volume; (275 µl) / 10 = X
X = 27.5 µl
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