Guthrie's bacterial inhibition test detects:

Guthrie's bacterial inhibition test:- Screening test for phenylketonuria (PKU) Used to detect the abnormal presence of phenylalanine metabolites in blood i.e. Phenyl pyruvate Phenyl alanine Phenyl lactate. Procedure: A small amount of blood sample is taken from heel of the infant and placed in a medium with a strain of Bacillus subtilis, a bacteria that cannot grow without phenylalanine. If phenylalanine metabolites are present, then these bacteria reproduce, and the test result is positive, indicating that patient has PKU.