The surfacedisplayed
single chain variable fragment (scFv) and phage
DNA themselves can serve directly as detection antibody and
PCR template, respectively. The target antigen is captured
by the immobilized capture antibody coated on a microtitre
plate, whilst the recombinant phage particles are anchored
through the interaction between the displayed scFv and
bound target antigen. The phage DNA is released by heat
lysis and serves as PCR template for amplification. PD-IPCR
has merits over conventional I-PCR, as the recombinant
phage particles carry both scFv and DNA to be amplified
and they can easily be obtained by simply centrifuging
the overnight Escherichia coli culture broth. However, the
sensitivity of PD-I-PCR is not as high as that of mAb-based
I-PCR due to the lower affinity of scFv towards the antigen.