hCG Midstream Test
- Handling time
The ultimed hCG Midstream Pregnancy Test is a rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotropin in urine to aid in the detection of pregnancy. The test indicates if the defined cut-off value has been exceeded or not. The ulti med pregnancy test is determined for the in vitro diagnostic use in laboratories or physicians’ offices.
The human chorionic gonadotropin hormone (hCG) is a glucoprotein consisting of an a and a b subunit, which is passed initially by the fertilised ovum and after implantation of the ovum in the mucous membrane of the uterus by this into the maternal blood circulation. In the normal course of pregnancy, hCG can be detected in the serum around seven days after fertilisation of the ovum (1 – 4). The hCG concentration has frequently risen above 100 mIU/ml 14 days after fertilisation of the ovum, therefore at the time when the otherwise expected period is missed. Concentration peaks of 200000 mIU/ml and more can be observed in the 10th to 12th week of pregnancy (2 – 4). The early rise of the hCG concentration even before the period is missed qualifies the hCG hormone for the early detection of pregnancy.
The ultimed hCG pregnancy test is set to a sensitivity of 25 mIU/ml. Both subunits are acquired by complex formation in the course of the test. Monoclonal antibodies, which because of their immunological specificity do not interact with the structurally related human follicle-stimulating hormone (hFSH), human luteinising hormone (hLH) and human thyroid-stimulating hormone (TSH) if these are present in physiological concentrations, are used in the test for selective detection of hCG concentrations in urine samples.
The ultimed hCG pregnancy test is a sandwich immunoassay for the fast detection of hCG in urine. The special membrane is placed in front of a reaction pad which contains colloidal gold particles coated with monoclonal anti-hCG antibodies. If a sample is applied, the colloidal gold particles dissolve in the liquid sample. If the sample contains the hCG hormone, this is bonded to the monoclonal antibodies marked with colloidal gold particles. The dissolved gold particles are transported through the membrane due to the capillary forces effective in the special membrane. In the area of the T-line, the anti-hCG antibodies immobilised there form the complex of hCG and colloidal gold. A more or less intensive red line is formed depending on the hCG concentration. The surplus colloidal gold particles are then bonded in the area of the C-line by the antibodies immobilised there, so that a red line also becomes visible in this area. This line serves as an internal functional check and must be formed in every test. If no or only very little hCG is contained in the sample (< 25 mIU/ml), the hormone-gold particle complex is not formed or it is formed in insufficient amount to generate a visible red line in the area of the T-line.