Diagram of typical immunoassay home pregnancy test which detects human chorionic gonadotropin (hCG). (A) A urine sample is applied to the stick. If pregnant, this should contain hCG. (B) As the sample is absorbed into the stick it goes through free dye-labeled antibodies that recognize and stick to hCG. (C) An anchored set of antibodies stick to and capture hCG molecules (and the attached dye-labeled antibodies), creating the first line. In the "not pregnant" sample no hCG is attached to the dye-labeled antibodies, so they wash past this point and no line appears. (D) A second anchored set of antibodies captures the dye-labeled antibodies, providing a positive control to indicate that the test is working properly.
What are the Clinical Indications for performing the Human Chorionic Gonadotropin Test?
How is the Specimen Collected for Human Chorionic Gonadotropin Test?
Sample required: Most commonly urine is collected; sometimes, blood may also be used.
What is the Significance of the Human Chorionic Gonadotropin Test Result?