u00b0 c for 1 minute annealing at 58 u00b0 c for 1 minute and extending at 72 u00b0 c for 115 minutes the cycle was repeated 30 times before the reaction mixture was kept at 72 u00b0 c for 10 minutes the amplified product is sequenced and the sequences of variable regions of the heavy chain and light chain of clone 1 10 and 11 of hybridoma are shown below the fc fragment of the constant region of the heavy chain and the u03ba u03bb constant region of the light chain from human blood cells beijing blood institute were cloned into the plasmid pcdna3 1 see walls m a hsiao h and harris l j 1993 nucleic acids research vol 21 no 12 2921 2929 for modification said sequence fragments of the heavy chain and light chain described in example 6 were synthesized by genscript corporation the heavy chain sequence fragment after digestion by xho i and age i enzymes and the light chain sequence fragment after digestion by sma i and dra iii enzymes were cloned into the plasmid pcdna3 1 and sequenced to confirm the sequence of cloned dna the experimental materials in the description below were all obtained through transfecting the cells with this series of plasmids and purifying the products generated by the transfected cells in vitro stimulation of t cells by chimeric antibody tetanus toxin stimulation test freshly prepared peripheral blood mononuclear cell pbmc were placed into 96 well flat bottom plate after an overnight incubation various concentrations of antibodies and 100 ng ml of tetanus toxin tt list biological laboratories were.