This proposal is a biochemical-immunological approach to a biochemical assessment, isolation and characterization of immunobiologically active RNA molecules able to transfer tumor-specific and/or chemically defined-specific sensitivity to lymphoid cells. Objectives include the following: (1)\To isolate and fractionate RNA from lymphoid tissues of syngeneic strain-2 guinea pigs immunized against line-1 or line-10 tumors, or other nontumor antigens, KLH or ARSNAT. (2)\Each RNA fraction is assessed for its ability to transfer tumor or other antigenic-specific sensitivities to guinea pig peritoneal exudate cells in vitro, utilizing the agarose droplet cell-migration-inhibition correlate of delayed type hypersensitivity and the thymidine incorporation assay. (3)\Fractions of RNA capable of converting lymphoid cells are purified by oligo-dT-cellulose chromatography and polyacrylamide gel electrophoresis. (4)\The RNA fraction which is biologically active is being used as templates for c-DNA copy development. Several cDNA products have been cloned in plasmid pBR322. RNA from clones containing hybrid plasmid DNA are being tested for biological activity. (5)\DNA from the active clones are being further characterized biochemically. (6)\Fractions of RNA capable of converting lymphoid cells will be characterized further as to their homogeneity and/or heterogeneity of the biologically active RNA species and the number of RNA molecular species found in the active extracts. (7)\The molecular weight and class of RNA to which the active species belongs is being assessed and are found to range from 4.0 x 105 to 8.5 x 105 in molecular weight. So far, biologically active RNA binds from acrylamide gels containing multiple species of RNA have been found in both the sucrose-derived and poly A-containing fractions. In order to achieve homogeneous species of RNA, a unique, innovative method of fusing RNA-converted murine spleen cells in developing RNA-derived hybridomas has been developed. One RNA-derived line has been positive for specific KLH antibody for a period of 257 days. Such RNA-derived hybridomas are being used for further identification and/or purification of RNA and for demonstration of serial transfer.