Invitrogen™ Human Tau (Phospho) [pT181] ELISA Kit

Description

Kit is designed to detect and quantify the level of Tau (Phospho) [pT181] in human cerebrospinal fluid, tissue homogenates, buffered solutions and cell culture supernatants. The assay recognizes both natural and recombinant Tau (Phospho) [pT181]. Principle of the method A monoclonal capture antibody specific for Tau (Phospho) [pT181] has been coated onto the wells of the 96-well plate. During the first incubation, standards of known content and unknown samples are pipetted into the wells and the antigen binds to the immobilized (capture) antibody. After washing, a rabbit antibody specific for the target protein is added to the wells and serves as a detection antibody by binding to the immobilized protein captured during the first incubation. After washing, a horseradish peroxidase labeled anti-rabbit IgG is added. This binds to the detection antibody to complete the four member sandwich. After a third incubation and washing to remove all the unbound enzyme, a substrate solution (TMB) is added, which is acted upon by the bound enzyme to produce color. The intensity of this colored product is directly proportional to the concentration of target protein present in the original specimen and the optical density can be read on a standard microplate reader. Rigorous validation Each manufactured lot of this ELISA kit is quality tested for criteria such as sensitivity, specificity, precision, and lot-to-lot consistency. See manual for more information on validation.

Tau is a neuronal microtubule-associated protein found predominantly on axons. The function of Tau is to promote tubulin polymerization and stabilize microtubules. The C-terminus binds axonal microtubules while the N- terminus binds neural plasma membrane components, suggesting that tau functions as a linker protein between both. Axonal polarity is predetermined by TAU/MAPT localization (in the neuronal cell) in the domain of the cell body defined by the centrosome. The short isoforms allow plasticity of the cytoskeleton while the longer isoforms may preferentially play a role in its stabilization. In its hyper-phosphorylated form, Tau is the major component of paired helical filaments (PHF), the building block of neurofibrillary lesions in Alzheimer's diseases (AD) brain. Hyper-phosphorylation impairs the microtubule binding function of Tau, resulting in the destabilization of microtubules in AD brains, ultimately leading to the degeneration of the affected neurons. Numerous serine/threonine kinases phosphorylate Tau, including GSK-3beta, protein kinase A (PKA), cyclin-dependent kinase 5 (cdk5) and casein kinase II. Hyper-phosphorylated Tau is found in neurofibrillary lesions in a range and other central nervous system disorders such as Pick's disease, frontotemporal dementia, cortico-basal degeneration and progressive supranuclear palsy.