If Western blots can confirm false positive results from ELISA, then Ydont we use Westerns in the first place.

Question

If Western blots can confirm false positive results from ELISA, then Ydont we use Westerns in the first place.

Answer 1

ELISA tests are perfect as something called screening or initial tests because

(1) multiple samples can be analyzed at the same time

(2) they can be done rapidly and

(3) they are more economical

Western blots are quite the opposite: (1) they require much more time...as much as 1 or 2 days depending on how busy the lab is, and because of this they are more costly in terms of labor (2) they require a more skilled technician.

Thus they would be used to confirm whether an ELISA test was a false positive.  This is especially critical, for instance, if an ELISA test shows that you are positive for HIV, which is the cause of the possibly fatal AIDS illness.  Before you take any treatment, you would want a CONFIRMATORY test result...that is a test of a different kind that also shows positive.  The probability of two false positives using different techniques is quite low.