双单抗的免疫层析一步法用于早妊诊断的研究

在试管式、微孔式和斑点式的酶免测定法测定人绒毛膜促性腺激素（ＨＣＧ）的基础上，发展了应用双单克隆抗体的免疫层析一步法测定ＨＣＧ。此法用胶体金标记抗βＨＣＧ单克隆抗体，将抗αＨＣＧ单克隆抗体包被在硝酸纤维素膜上。无需分离步骤，特别是在进行测定时除加入样品外无需再加任何试剂，此方法特别迅速、简便，２～５ｍｉｎ即可得结果。凡ＨＣＧ浓度＞２５ＩＵ／Ｌ的样品可得到阳性结果。在人体血或尿中可能出现的高浓度的干扰物质，如抗坏血酸、乙酰水杨酸、雌二醇、蛋白质、胆红素、甘油三酯等对本测定均无干扰作用，在促黄体激素（ＬＨ）浓度高达５００ＩＵ／Ｌ时仍与ＨＣＧ没有交叉反应。能进行测定的最高值大于３００ＩＵ／ｍｌ，这表示，当ＨＣＧ浓度达到妊娠期的最高值时仍不会有假阴性结果。

Studies on a Immunochromatographic One-step Method Using Two Monoclonal Antibodies and Its Application in the Diagnosis of Pregnancy

For the heterogeneous immunoassay,it is necessary to have a step of separation between bound labeled ligand and free labeled ligand. An immunochromatographic one-step method based on two monoclonal antibody (McAb) sandwich assay have been developed to determine human chorionic gonadotropin (HCG). There is no requirement for a separation step. Gold colloid was prepared and was used to label the McAb against β subunit of HCG,and another McAb against a subunit of HCG was coated on the nitrocellulose membrane. This method is extremely simple, the only thing we have to do is to dip the lower end of the test strip into the urine sample. No any other reagents are required during the assay. Also it is very fast. The result comes out within 2-5 minites. Our results indicated that all the HCG standard solutions containing HCG higher than 25 mIU/ml showed positive results, and all the controls which contained no HCG showed negative results. The high concentration of some substances,such as ascorbic acid, acetylsalicylic acid, estriol, protein, bilirubin, triglyceride, etc. were tested in HCG free urine and urine containing 200 mIU/ml HCG. None of the substances, at the concentration tested, interferred with the assay. There was no cross-reaction with the leuteinizing hormone (LH),when the concentration of the latter was as high as 500 mIU/ml. The HCG concentration as high as 300 IU/ ml,still showed positive result.This means that the urine smaple obtained at maximum concentration of HCG during pregnancy does not give false negative result.