PGGT monoclonal antibodies were prepared by hybridization technique. The sera of 217 patients and 40 normal controls were examined by using ELISA with PGGT as antibodies for differentiation diagnosis of carcinoma of head of pancreas, liver cancer, malignant tumors and benign obstruction. The results revealed that the sensitivity, specificity and precision of PGGT method in diagnosis of cancer of head of pancreas were, respectively, 100% and 99.6% with precision being 99.6%. The negative ancl positive predic...