2.5 M CaCl2 (20 ml)Weigh out 13.5 g CaCl2?H2O and dissolve in 15 ml of distilled water.Make up volume to 20 ml with distilled water.Sterilize the solution by filtration through a 0.22 micron filter. <STORAGE> Store in 1 ml aliquots at -20 C.Related Posts:1 M CaCl2 (200 ml)0.1 M Adenosine triphosphate (ATP)(1 ml)30% Acrylamide (100 ml)40% Acrylamide (for DNA sequencing)(1 liter)10 % Ammonium persulfate (10 ml)Deoxyribonucleoside triphosphates (dNTPs)