urine tests

Question 1

pregnancy

Answer 1

detect human chorionic gonadotropin in urine of pregant women

1) stick is used with an application area that contains monoclonal antibodies for hCG bound to a coloured bead(blue). monoclonal antibodies are all identical to each other
2) when urine is applied to the application area any hCG will bind to the antibody on the beads
3) urine moves up the test strip, carying the beads with it
4) the test strip has antibodies to hCG immobilised
5) if there is hCG present the test strip turns blue because the immobilised antibody binds to any hCG attached to the blue beads, concentrating the blue beads in that area. If no hCG is present, the beads wont pass through the test area without binding to anything, and so it wont go blue