Subject: How scientist determine the chemicals required for the isolation of DNA.

There is huge list of chemicals (organic and inorganic). we are using about 10 
chemicals to isolated DNA from organism with predefined protocol.
How scientists selcted these chemicals perticularly for the isolation of DNA. 
because there are lot of chemicals having more or less same action or 
specificity. 
for example Tris is mostly used in different protocol..
How this complex stuctured chemical came in focus....what are the critierias 
scientists used to select that one and how did they do it.

Re: How scientist determine the chemicals required for the isolation of DNA.