S. T. Isaacs

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We describe a photochemical procedure for the sterilization of polynucleotides that are created by the Polymerase Chain Reaction (PCR). The procedure is based upon the blockage of Taq DNA polymerase when it encounters a photochemically modified base in a polynucleotide strand. We have discovered reagents that can be added to a PCR reaction mixture prior to(More)
PERSPECTIVES AND UMMARY .............................................................. 1152 INTRODUCTION ..................................................................................... 1155 ORGANIC AND STRUCTURAL CHEMISTRY OF PSORALEN AND ITS ADDUCTS ................................................................... 1158 Naturally Occurring Psoralens(More)
In searching for a nucleic acid within the scrapie agent, we employed psoralens which penetrate the coats of most conventional viruses, form photoadducts with their genomes. and block replication of the viruses. Five psoralens, at concentrations up to 500 times greater than those required to inactivate conventional viruses, did not influence scrapie agent(More)
Four psoralen derivatives were radiolabeled and used for in vitro DNA binding studies. The derivatives were compared for their dark-binding ability to DNA, photoreactivity, and for unwinding angles. The dark-binding dissociation constants we determined were 1.4 X 10(-3) M for 8-methoxypsoralen (8-MOP), 3.5 X 10(-4) M for 5-methoxypsoralen (5-MOP), and 5.5 X(More)
We have developed an effective post-PCR sterilization process and have applied the procedure to a diagnostic assay for HIV-1. The method, which is based on isopsoralen photochemistry, satisfies both the inactivation and hybridization requirements of a practical sterilization process. The key feature of the technique is the use of isopsoralen compounds which(More)
BACKGROUND A photochemical treatment process has been developed for the inactivation of viruses and bacteria in platelet concentrates. This process is based on the photochemical reaction of a novel psoralen, S-59, with nucleic acids upon illumination with long-wavelength ultraviolet light (UVA, 320-400 nm). STUDY DESIGN AND METHODS High levels of(More)
The carryover of previously amplified sequences (amplicons) into new PCR reactions is a serious problem. Recently Furrer et al. reported a 'pre-PCR' sterilization technique using DNase I or restriction enzymes for contamination control (1). Unfortunately, these methods require the reaction tube to be re-opened to add target DNA and Taq polymerase following(More)
2-Acetoxymethyl-1,4-naphthoquinone (2-AcOMeNQ) binds with rapid kinetics and high affinity to the primary quinone Q(A) site of reaction centers from Rhodopseudomonas capsulata. Binding of 2-AcOMeNQ fully restores electron-transfer activity with kinetics that is similar, but not identical, to that seen with ubiquinone-50. When bound at the Q(A) site,(More)