[82] Use of DNA bound to filters for selection of interferon-specific nucleic acid sequences

Publisher Summary This chapter presents the use of DNA bound to filters for selection of interferon-specific nucleic acid sequences. For the selection of a cloned interferon cDNA sequence, the most sensitive and specific method depends upon hybridization of interferon mRNA to plasmid DNA covalently bound to diazobenzyloxymethyl (DBM) paper followed by elution and translation of the mRNA. This selection method is based upon the procedures and has been used to select plasmids carrying segments of the Xenopus laevis vitellogenin gene. Modifications of this procedure have also been used to identify plasmids containing part of the gene for human leukocyte interferon. Plasmid DNA to be analyzed is isolated by the cleared lysate procedure and purified by centrifugation in a CsC1 equilibrium density gradient. It is necessary to include the negative controls to identify plasmids containing interferon sequences.