RBCs were added to 293 cells transfected with mutated DNA-HA vectors to cover cell monolayer. Results for RBC adsorption indicate that cells transfected with the 83NNT, 86NNT, 94NFT, 127NSS, 138NRT and 161NRS vectors retained their hemadsorption function, while cells transfected with the 156NTT, 183NDT and 252NAT vectors did not. Cells transfected with a wild-type DNA-HA vector were used as a positive control (PC); cells tranfected with an empty vector were used as a negative control (NC).