A Medical Laboratory Scientist Performs Fluorescence in Situ Hybridization (FISH)

Multiple Choice

A medical laboratory scientist performs fluorescence in situ hybridization (FISH) on interphase chromosomes using a probe to chromosome 21. In all cells examined, two signals were seen. These results are interpreted as:

A) Normal
B) Abnormal; the patient has Down's syndrome
C) Abnormal; the patient is lacking a copy of chromosome 21
D) Abnormal; the patient has a Philadelphia chromosome