ELISA is performed on a population with low prevalence. What would be the result of performing double screening ELISA tests -
The specificity of ELISA can be increased by carrying out ELISA in a row (series) using different HIV markers.
When screening test is used in a series mode : -


↑ Specificity
↑ PPV
↓ Sensitivity
Increased sensitivity and positive predictiv value
Increased sensitivity and negative predictive value
Increased specificity and positive predictive value
Increased specificity and negative predictive value