Isolation, Characterization, and Molecular Modeling of a Rheumatoid Factor from a Hepatitis C Virus Infected Patient with Sjögren's Syndrome

Lee, Yu-Ching; Tsai, Keng-Chang; Leu, Sy-Jye; Wang, Tuan-Jen; Liu, Chia-Yu; Yang, Yi-Yuan

15 clones were randomly selected to check the presence of DNA inserts with correct length. The results showed that more than 90% of the clones contain a fragment of 750 bp in plasmid DNA after second around panning (data not shown), indicating that the panning eliminated most of the phage clones not displaying Fab fragments on their surfaces, which accounted for less than 10% of phage clones in the original antibody library we constructed. Thereafter, the gene III fragment was removed from phagemid DNA purified from E. coli culture after 4th panning. The expression of IPTG-induced Fab antibodies under the nonreducing condition was clearly detected and shown in Figure 1(b) . With the exception of one clone with incomplete nucleotide sequence, the immunoglobulin isotyping anaysis indicated that 13 of 14 RF molecules contained light chain. We did not find any antibody with light chain.