Mh. Hansen et al., DETECTION OF PNA DNA HYBRID MOLECULES BY ANTIBODY FAB FRAGMENTS ISOLATED FROM A PHAGE DISPLAY LIBRARY/, Journal of immunological methods, 203(2), 1997, pp. 199-207
We have isolated Fab fragments that specifically recognize duplexes fo
rmed between DNA and PNA (peptide nucleic acid) from an immunized muri
ne phage display library. Rearranged murine Fd- and Kappa chains were
assembled by PCR and cloned into a phagemid expression vector. Subsequ
ently, affinity selection on immobilized PNA/DNA duplexes of the Fab-d
isplaying phages resulted in the isolation of clones that uniquely rec
ognized PNA/DNA duplexes. One of these clones was characterized in det
ail, and its recognition of PNA/DNA duplexes was relatively sequence i
ndependent, taking place equally well with sticky-end and blunt end PN
A/DNA duplexes. Duplexes smaller than 15-mers could not be detected. T
he selected clone recognized neither single-stranded DNA and PNA, nor
double-stranded DNA and PNA. Binding of the Fab fragments to immobiliz
ed PNA/DNA duplexes could be inhibited by PNA/DNA duplex molecules in
solution, with an apparent affinity in the nanomolar range. The use of
this anti PNA/DNA Fab-phage as an immunochemical reagent was demonstr
ated in dot blot assays.