Strongly basic medium decomposes artesunate and this procedure has been suggested as a means of
indirect assay for artesunate.
The antibody used for capture and the second Ab labeled with biotin (used in the
indirect assay) or PE (used in the direct assay) are available from PharMingen in San Diego, CA.
In none of the clinical specimens we examined did we discover the quantities of hCGn found by other investigators using
indirect assay methodologies.
The PRA assay is an
indirect assay of renin and is complicated by the fact that Ang I is usually converted to Ang II and degraded into smaller inactive peptides.
In case of indirect tests the HCV infection or exposure to HCV is indirectly detected; based on the presence or absence of antibodies (IgM or IgG) to HCV.9 One of the limitations of
indirect assays is their inability to discriminate between active or past infection.
In general, the ratio of hits between direct and indirect is much less than the overall ratio of the number of direct to
indirect assays. Some chemicals show a large number of hits against direct targets.
A common format is to coat the ELISA plate with antibody for direct assays, or antigen for
indirect assays. ELISA plates are subsequently "blocked" to prevent any further nonspecific absorption.
These include direct measurement of in vivo oxidative stress and also
indirect assays, e.g., susceptibility of lipoproteins such as LDL to oxidative stress.
The Integra ion-selective electrode (ISE) module is designed to quantify Na, K, Cl, and Li in serum and plasma by direct assays of undiluted samples or
indirect assays of diluted samples.