2X SDS-PAGE Sample BufferThis product is a concentrated stock solution and should be diluted appropriately with distilled, deionized water or equivalent to its final working concentration. 2X SDS-PAGE Sample Buffer consists of 0.125 M Tris-HCl, 4% (w/v) SDS, 20% (v/v) Glycerol and 0.01% (w/v) bromophenol blue. The pH of this solution is 6.8. Meticulously prepared using ultra pure reagents dissolved in highly polished pharmaceutical grade deionized water.This product was aseptically filtered through a Millipore 0.22 micron filter into clean, pre-sterilized containers. The product was tested on trypticase soy agar for 24 hours, 48 hours and 72 hours and was found to be negative for bacteria.See kit insert for complete instructions.