In this study we selected by phage display several new antibodies against human CD33. We then tested them in a variety of immunodetection assays, in parallel with previously described recombinant antibodies as well as commercial antibodies. The reactivity of individual antibodies varied strongly depending on the method used for immunodetection. The results demonstrate that the recombinant antibodies achieve performance comparable to the animal-derived antibodies.
In this study we selected by phage display several new antibodies against human PD-1: the ABCD_RC105 nanobody and ABCD_RC226, RC227 and RC229 human antibodies. We then tested them in a variety of immunodetection assays, in parallel with a previously described therapeutic antibody (ABCD_AS298). The newly discovered antibodies recognize the human PD-1 protein in ELISA and immunofluorescence assays and, albeit less efficiently, by western blot. The newly generated recombinant antibodies exhibited performance comparable to that of newly developed animal-derived antibodies.
The engineered Forkhead-associated Domain (FHA1), located at the N-terminus of the RAD53 protein of Saccharomyces cerevisiae, was shown in previous studies to specifically recognize the phosphorylated peptide of the p53-binding protein (53BP1). When the engineered FHA1 domain was expressed as a recombinant rabbit Fc-fusion protein, it still recognized the phosphorylated 53BP1 peptide in an ELISA. FHA1-Fc fusion proteins can thus be used as specific antibodies to identify the phosphorylation status of various proteins.
The recombinant antibodies ABCD_AF632, ABCD_AQ776, ABCD_AS298, ABCD_AS299 and ABCD_AS300 detect by immuno-cytometry the human protein PD-1 at the surface of HeLa cells.
