Summary Pregnancy Testing

Pregnancy Testng
Early Pregnancy Factor (EPF)
 Rosette inhibiton assay
 Gives quickest result - 48hrs afer fertllsaton
 Expensive and tie consuiing

βhCG Test
 Cheiical pregnancy tests look for the beta subunit of huian chorionic gonadotrophin (βhCG)
 A horione (glycoprotein) produced by the placenta (partcularly the sycncytotrophoblast) afer
iiplantaton of the eibryo
 Detectable afer iiplantaton 6-12 days afer fertllsaton
 Starts to show positve when blood is at >20iU
 Can be detected in either urine or blood


The urine test strip uses the ELISA iethod to detect the cheiical.
 There are 3 zones on the strip:
- Reacton zone: Contains soluble iouse ant-hCG antiody enzyyee conjyugates
- Test zone: Contains iiiobilised poly-clonal ant-hCG antiodles and a dye suistrate
- Control zone: Contains iiiobilised goat ant-eouse antiodles and a dye suistrate
 In a positve test:
1) Reacton zone: hCG binds to the iouse ant-hCG antbody and are carried along
2) Test zone: the hCG-bound iouse ant-hCG antbodies arrive in the test zone and bind to the iiiobilised
polyclonal hCG antbodies. This actvates the dye
3) Control zone: Any of the unbound iouse ant-hCG antbodies froi the reacton zone bind to the
iiiobilised ant-iouse antbodies. - This actvates the dye
4) Result  Two coloured strlps
 In a negatve test:
1) Reacton zone: unbound iouse ant-hCG antbody and are carried along
2) Test zone: the ant-hCG antbodies arrive in the test zone but do not bind to the iiiobilised polyclonal
hCG antbodies. Dye is not actvated
3) Control zone: All of the unbound iouse ant-hCG antbodies froi the reacton zone bind to the
iiiobilised ant-iouse antbodies. - This actvates the dye
4) Result  One coloured strlp