SUPERIORITY OF IN-SITU HYBRIDIZATION OVER IMMUNOLABELING FOR DETECTING DNA ON LOWICRYL SECTIONS - A STUDY ON ADENOVIRUS-INFECTED CELLS

We investigated the intranuclear distribution of viral genomes in aden ovirus Type 5-infected HeLa cells on ultra-thin sections of Lowicryl K 4M-embedded material by immunolabeling of DNA and in situ hybridizatio n with a viral DNA probe. Monoclonal AC-30-10, raised against double- and single-stranded DNA (dsDNA, ssDNA), and HB2 antibodies, raised aga inst only the dsDNA, were used. Both antibodies intensely labeled the condensed host chromatin and the virus-induced substructures containin g inactive encapsidated and non-encapsidated viral genomes. The antibo dies labeled only slightly those substructures containing replicating and transcribing viral genomes. Viral ssDNA, which is accumulated with in well-delineated compact fibrillar structures, was not revealed by A C-30-10 even after elimination of the proteins of the section. In situ hybridization detected all of these types of viral DNA, depending on the protocol used. Therefore, the sensitivity of in situ hybridization for detecting DNA appears superior to immunolabeling with specific an tibodies.