QUALITY-CONTROL, ANALYTIC SENSITIVITY, AND THE POLYMERASE CHAIN-REACTION

The polymerase chain reaction (PCR) has provided a potentially practic al means of analyzing DNA and RNA for the clinical laboratory. Manufac turers are beginning to produce test kits based on this technology. As a qualitative test, key performance characteristics need to be unders tood and defined for each application. The cutoff and the gray zone ar ound the cutoff are all quantifiable in terms of copy number or concen tration for PCR tests. These characteristics, along with the type of s pecimen and the clinical purpose of the test, develop a framework in w hich quality control can be considered. This should provide the basis for elaboration of effective statistical and nonstatistical quality co ntrol procedures. The level of the cutoff (the analytic sensitivity) a nd its relation to the specimen copy number and clinical test purpose highlight the use of this approach.