Hot borate extraction buffer (pH 9.0)

Recipe

Reagent	Amount to add (for 10 mL)	Final concentration
XT buffer (pH 9.0)	5 mL	50%
1 M DTT	0.05 mL	0.5%
IGEPAL CA-630 (Sigma)	0.1 mL	1%
Polyvinylpyrrolidone (PVP) (MW 40 kD) (Sigma)	0.2 g	2%

All reagents should be RNase-free. Mix all reagents just before use and incubate borate extraction buffer at 80°C for at least 10 min before adding to sample.
This recipe provides sufficient buffer for one sample using 2 g of tissue; for more than one sample, multiply the reagents by the total number of samples plus one.