title: Factors influencing the enhancement of the infectivity of poliovirus ribonucleic acid by diethylaminoethyl-dextran.
abstract: The enhancement by diethylaminoethyl-dextran (DEAE-D) of the infectivity of poliovirus ribonucleic acid (RNA) for cell cultures was demonstrated by infective-center as well as by plaque assays, both in nonprimate (L) and primate cell systems (MK, HeLa, LLC-MK(2)). The sensitivity of plaque assays was greatly improved by using a tris (hydroxymethyl)aminomethane-buffered synthetic medium (basal medium Eagle) and freshly confluent cell monolayers. Enhancement of nucleic acid infectivity was directly dependent on the molecular weight of the DEAE-D. Two observations bearing on the action of DEAE-D appeared important: ribonuclease activity was reduced by DEAE-D, and cells pretreated with DEAE-D remained susceptible to infection with RNA in isotonic medium. Appreciable susceptibility of the treated cells persisted for at least 2 hr; the susceptible state could be reversed at will by an application of heparin. Enhancement of nucleic acid infectivity was independent of an effect of DEAE-D on intact virus and agar inhibitors.
mesh_terms: D000818:Animals; D002460:Cell Line; D046508:Culture Techniques; D003911:Dextrans / Q000494:pharmacology*; D000882:Haplorhini; D006367:HeLa Cells; D007668:Kidney; D007739:L Cells; D017955:Poliovirus / Q000472:pathogenicity*; D012367:RNA, Viral
chemical_list: D003911:Dextrans; D012367:RNA, Viral