The accumulation of amyloid beta protein in the cerebral cortex in Alzheimer's disease (AD) is only one of the outcomes of proteolytic cleavage of amyloid precursor protein (APP). More than 50 different mutations in the APP gene can cause early-onset Alzheimer disease. Cleavage by beta- and gamma-secretase (amyloidogenic pathway) leads to production of amyloid-beta and soluble APP-beta, while cleavage by alpha-secretase (nonamyloidogenic pathway) results in a soluble form of APP, sAPP-alpha. Several mutations in the SAPP gene can give rise to variants of both SAPP-alpha and sAPP-beta.
These kits are solid-phase sandwich ELISAs using two antibodies that are highly specific to human sAPP variant proteins; one is precoated on the ELISA plate and the other is HRP-conjugated. These kits can be used to measure human sAPP variants in serum, EDTA plasma, cerebrospinal fluids, or cell culture supernatant.