Schematic illustration of TS-jPCR. (A) Diagram showing the specific V gene joining with the Ig-cassette. (B) Diagram showing the mechanism by which TS-jPCR inhibits the joining of nonspecifically amplified DNA to the Ig-cassette. P3 and P4 are primers that hybridize to the f1 replication origin sequence localized between the CMV promoter and the poly (A) signal under a low annealing temperature. NNN indicates the 3'-end random-nucleotide tail.