Pregnancy Tests

• Monoclonal antibodies play a crucial role in pregnancy tests, as pregnant women produce a hormone called hCG which is excreted in their urine.
• The key idea behind pregnancy tests is that they can detect the hCG chemicals in urine, indicating whether a woman is pregnant.
• The test kit consists of a test strip with two important parts: a bunch of monoclonal antibodies specific to hCG on the right side, and blue beads covered in the same monoclonal antibodies on the left side.
• The monoclonal antibodies on the test strip are fixed, meaning they can't move, while the beads and the antibodies they're attached to are completely free to move around.
• If the test is negative, the urine will wash the unfixed beads along the test strip, causing them to flow right over the fixed antibodies.
• If the test is positive, the hCG will bind to the antibodies on the blue beads, causing the beads to get stuck in place by trapping loads of these tiny blue beads.
• The entire test strip appears blue when it's positive, indicating a positive test result.
• Most pregnancy tests in real life have two lines rather than one, with the second line acting as a controller, meaning you normally need two lines for a positive result.
• Different tests work differently, so it's important to read the instructions before using any.