Enzyme-Labeled DNA Probes

Many research workers and clinicians working in routine laboratories are now using the “tools” developed by molecular biologists over the past 10 years to produce DNA sequences that can be used as probes to detect specific genes. Thus it is possible to screen food for salmonella (1 ) or other organisms in a test much more quickly than conventional methods involving culturing the organisms. The presence of certain types of human papillomavirus in cervical smears can be used as an indicationof neoplasia (2 ). DNA probes can also be used to screen antenatally for diseases such as sickle cells anemia (3 ) or β�-thalassemia (4 ).