C4 is an in vitro diagnostic assay for the quantitative determination of C4 in human serum or plasma. Antigen in the sample bonds to the specific antibody in the reagent, forming an immune complex. The immune complex causes an increase in light scattering, measured by reading turbidity at 604 nm, which correlates with the concentration of C4 in the sample.

Reason: An update to the Reagents and Specimen Collection and Handling/Preparation for Analysis sections of the IFU was required due to different issues with the various products.

Code information: All IFU's

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