Characterization of a new monoclonal antibody to triplex DNA and immunofluorescent staining of XXXX chromosomes.

@entity1 @entity1522 @entity19 @entity71383 @entity535 @entity71382 @entity71381
A monoclonal antibody, Jel 466, was prepared from @entity19 immunized with @entity71381 . The binding of Jel 466 to nucleic acids was characterized by solid phase radioimmunoassays and competition experiments. There was no binding to single-stranded DNAs or to duplexes which could not form triplexes. In addition, the antibody preferred the triplex form of @entity71382 ; it bound weakly to the triplex derived from @entity71383 , but there was no interaction with poly[d(T)].poly[d(A)].poly[d(T)]. This pattern of specificity is very different from that of Jel 318, a triplex-specific antibody that will bind to poly[d(T)].poly[d(A)].poly[d(T)]. The @entity535 sequence of Jel 466 also showed very little homology with Jel 318, although both contain many positively charged @entity1522 . The immunofluorescent staining of @entity19 and @entity1 chromosomes with Jel 466 was studied. In all cases, there was a marked reciprocal relationship between the pattern of Jel 466 on the one hand and that of Hoechst 33258 and Jel 318 on the other. Jel 466 was negative for C-band and G-band but positive for R-band, whereas the opposite was found for Hoechst and Jel 318. Since C and G-bands are AT-rich and R-bands are GC-rich, these staining patterns match the sequence preferences of the two antibodies. Thus the base composition of triplex-forming DNA differs from domain to domain.
