| 摘要 |
A quantitative screening protocol for the assay of tumor globulin which is separated from gastric juice of human patients at risk for gastric cancer comprising a purification procedure by column chromatography to recover tumor globulin from the gastric aspirate followed by a quantitative detection procedure in which the tumor globulin antigen from gastric juice which has been enriched in the separation process. The enriched tumor globulin is tested by ELISA quantitative assay using avidin/biotin/horseradish peroxidase. The preferred column is in the form of agarose beads covalently linked to both of diethylaminoethyl groups and Cibacron Blue F3GA. The protocol of the invention provides an improved screening of at risk patients to obtain early diagnosis of gastric cancer which is an improvement of applican's prior U.S. Pat. No. 4,219,539 granted Aug. 26, 1980. The sensitivity of the diagnostic method of applicant's aforesaid U.S. Pat. No. 4,219,539 is adequate to detect 250 nanograms/ml of gastric cancer juice antigen per ml of sample. The present ELISA method detects as little as 0.2 nanograms per ml of tumor IgG and suprisingly gastric cancer samples are at a higher level than in patients having normal gastric juice, e.g. varying from about 4 to about 33 nanograms of IgG per mg of protein which is concentrated by column chromatography.
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