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将纯化的宋内痢疾杆菌脂多糖的鼠单克隆抗体（５Ｂ１２）固相化，然后对混合噬菌体抗体库（ＨＩＶ、ＨＡＶ、ＨＢＶ）进行５轮“吸附－洗脱－扩增”的淘筛，使特异性噬菌体抗体得到了富集，阳性率达５３．１３％。竞争抑制试验证明，其中６株与宋内痢疾杆菌脂多糖的竞争抑制率大于５０％。酶切电泳图谱显示，淘筛的阳性克隆均无轻链基因，重链基因约４００ｂｐ。对分离的两株阳性克隆进行序列分析研究，发现这两个克隆ＤＮＡ序列相同，均为人免疫球蛋白重链可变区序列，属人ＩｇＧ基因Ⅲ家族，长度为３８４ｂｐ，与期望的６６０ｂｐ相差２７６ｂｐ。但这种重链部分缺失和轻链完全缺失的抗体片段却有明确的与５Ｂ１２的结合活性。
The purified murine monoclonal antibody (5B12) of Shigella dysenteriae lipopolysaccharide was immobilized and then subjected to 5 rounds of “adsorption-eluting-amplification” panning on a mixed phage antibody library (HIV, HAV, HBV) So that the specific phage antibody was enriched, the positive rate of 53.13%. Competitive inhibition test proved that 6 of them competed for inhibition of S. typhi LPS by more than 50%. The enzyme digestion electrophoresis showed that there was no light chain gene in the positive panning screen, and the heavy chain gene was about 400bp. Sequence analysis of the two isolated clones revealed that the two cloned DNA sequences were identical to human immunoglobulin heavy chain variable region sequences and belong to the human IgG gene Ⅲ family with a length of 384 bp and a difference of 276 bp from the expected 660 bp . However, this antibody fragment with partial deletion of the heavy chain and complete absence of the light chain has a clear binding activity to 5B12.