RESUMO
Highly reproducible results in molecular biology depend a lot on effective staining and destaining methods. Silver staining of polyacrylamide DNA and protein gel has been adopted widely in the molecular biology laboratories for detecting a very low nanogram range of sample. An efficient staining of a polyacrylamide gel requires a number of well controlled and highly sensitive steps that often becomes tiresome when done manually or when there are a number of gels to be stained simultaneously. Since, silver staining is a multistep procedure that requires proper fixation and exchange of substance, a reliable protocol is necessary and a simple apparatus may be an added advantage to carry out the steps with ease and safety. Here, we describe a simple and cost effective device made from off-the-shelf components for some established silver staining protocols. Staining is done on a tray while six graduated bottles with a liquid delivery stopcock each, is connected to the tray through silicon tubing. The used up solution is drained off completely from the staining tray through a liquid outlet stopcock using vacuum pressure. The system is fixed with a camera connected to a computer for effective control of the staining process in each step. The apparatus provides the researchers with efficient staining and real time monitoring of gels without the need for handling toxic chemicals.