A positive Guthrie test is interpreted by observing:
A) Bacterial growth occurs around the positive control disc and the patient disc
B) Bacterial growth occurs around the positive control disc but not around the patient disc
C) No bacterial growth occurs around either disc
D) Bacterial growth occurs only around the negative control disc

Question

Quizplus · Accepted Answer

A positive Guthrie test indicates that the patient's blood contains an abnormal amount of phenylalanine, which supports bacterial growth. Thus, bacterial growth occurs around both the positive control disc (which contains phenylalanine) and the patient disc (indicating the patient also has elevated levels of phenylalanine).

A Positive Guthrie Test Is Interpreted by Observing