A 40% (w/v) solution of ultra pure acrylamide (38.96%) and bis-acrylamide (1.04%) at a final ratio of 37.5:1. Reconstituted with deionized water, 40g size has a final volume of 100ml; 200g size has a final volume of 500ml. Reconstitution will produce a 40% (w/v) solution.