Buffer AB

Prepare 250 ml for 250 g of Drosophila embryos:

15 mM HEPES, potassium salt (pH 7.6)

110 mM KCl

5 mM MgCl₂

0.1 mM EDTA

Store at 4ºC. Just before use, add the following (to 250 ml):

1.25 ml DTT (0.5 M)

0.625 ml sodium metabisulfite (0.5 M)

0.31 ml PMSF (0.2 M) in ethanol

0.625 ml Benzamidine (0.5 M)