A laboratory is validating a new β-human chorionic gonadotropin assay. Below are the results from a validation study assessing potential carryover. The acceptable limit for carryover was set at 2 times the SD for the low concentration mean. According to this table, the calculated percent carryover is:
Diagnosis: Quality Control
• Carryover refers to the transfer of a quantity of an analyte from one reaction into the next subsequent reaction.
• Carryover of an analyte could potentially cause a false elevation in patient results and, therefore, should be assessed when validating a new test system, if applicable to the methodology.
• Accuracy can be assessed by measuring an analyte in reference material with a known concentration and comparing the result with the certified value.
• Precision is the agreement between result values obtained by repeat measurements of a quantity.
• The limit of detection is the lowest concentration of an analyte in a sample that can be reliably detected.
