Preparation of SM Buffer with gelatin

Reagent	Amount	Final concentration
NaCl	5.8 g	100 mM
MgSO4·7H2O	2 g	8 mM
Tris-Cl (1 M, pH 7.5)	50 ml	50 mM
Gelatin (2%, w/v)	5 ml	0.01% (w/v)
H2O	to 1 liter
To prepare 1 liter of SM buffer with gelatin, dissolve the NaCl and MgSO4·7H2O in 800 ml of H2O; add the Tris-Cl and gelatin; and adjust the volume to 1 liter with H2O. Sterilize the buffer by autoclaving for 20 minutes at 15 psi (1.05 kg/cm2) on liquid cycle. After the solution has cooled, dispense 50-ml aliquots into sterile containers. SM buffer with gelatin may be stored indefinitely at room temperature. Discard each aliquot after use to minimize the chance of contamination. To prepare SM Buffer without gelatin click here and to prepare Tris-cl click here