GCSE Biology - How do Pregnancy Tests Work? #41

The video explains how pregnancy tests work by detecting the hormone HCG in urine. It describes the role of monoclonal antibodies in the test strip, which bind to HCG if present. The test strip has fixed antibodies and free-moving blue beads with antibodies. If HCG is present, it binds to the beads, causing them to stick to the strip and turn it blue, indicating a positive result. The video also notes that most tests have two lines, with one acting as a control, and emphasizes reading instructions for different tests.

What is the key hormone that pregnancy tests detect?

What role do monoclonal antibodies play in pregnancy tests?

Explain the difference between the fixed antibodies and the free-moving beads in the test.

Describe how the test strip indicates a positive result.

Why is it important to read the instructions before using a pregnancy test?