An inexpensive method for the rapid identification of specific cDNAs from cDNA libraries.

The identification of specific cDNAs by screening filters impregnated with DNA from phage or bacterial colonies is a time-consuming and expensive undertaking. We have developed a rapid and inexpensive method for identifying specific cDNAs that involves hybridization of cDNAs to specific oligonucleotides bound to nylon filters. Using this method, we have identified specific cDNAs for a human B-cell growth factor from different cDNA libraries. The total processing time was 3 days, and 30% of the cDNAs selected by this method were correct.