Test Discontinuation – HIV-1 Western Blot (HIV1CO)
HIV-1 Western Blot Antibody Confirmation (HIV1CO) has been discontinued by the performing reference laboratory.
As an alternative, Cleveland Clinic Laboratories recommends HIV-1 p24 Ag + HIV-1-2 Ab, with reflex to differentiation (HIV12C) testing.
This test, which is performed in-house, follows the CDC-recommended screening algorithm of reflex to differentiation.
Cleveland Clinic Laboratories
Chemiluminescent microparticle immunoassay (CMIA)
Stability (after separation from cells)
Ambient: 72 hours
Refrigerated: 7 days
Frozen ≤ -20°C: 14 days
HIV screening and diagnosis
The screening assay is an antigen-antibody combination; when reactive, an HIV confirmatory assay is automatically added and performed.
The confirmatory assay is FDA-approved and can differentiate HIV-1 from HIV-2, making it an integral part of the testing algorithm.
If a client performs a fourth-generation screen, HIV-1/2 Ab Confirmatory (HIV12M) testing may be ordered following a repeatedly positive screen.