Template activity of RNA from antibody-producing tissues.

An RNA fraction, which represents a small percentage of cellular RNA and which has the characteristics of nuclear messenger RNA, has been isolated from the spleen and lymph nodes of immunized rats by successive phenol extractions of these tissues at increasing temperatures. This fraction increased the amount of protein synthesized in a cell-free extract of Escherichia coli as much as 35 times and directed the synthesis of proteins different from those of E. coli.