Human Phospho Tau ELISA Kit

Antibodies.com provides a sandwich Enzyme-Linked Immunosorbent Assay (sELISA) for the in vitro quantitative determination of human Tau phosphorylated at threonine 181 (phospho T181) in serum, plasma, tissue homogenates, and other biological fluids. The assay is specific for Tau (phospho T181), with no reported cross-reactivity with other analogs or variants.

The procedure uses a pre-coated microplate to which standards and samples are added; Tau (phospho T181) binds to the immobilised capture antibody. After washing, a biotinylated detection antibody is added to form an antibody–antigen–antibody sandwich. Following further incubation and washing steps, HRP-Streptavidin conjugate and TMB substrate are introduced, producing a blue product that turns yellow upon addition of stop solution. Absorbance is read at 450 nm and the concentration of Tau (phospho T181) is calculated by comparison with the standard curve. The complete assay time is 4 hours.

The standard curve covers 7.813–500 pg/mL with a sensitivity of <4.688 pg/mL. Detection is colorimetric (OD at 450 nm) on a pre-coated microplate arranged as 12 × 8 well strips. Reported average recovery values are 94% for serum (range 85%–104%, n=10), 91% for EDTA plasma (range 85%–99%, n=10), and 96% for heparin plasma (range 88%–105%, n=10). Validated sample dilutions include NAMALWA cell lysate (1:5) and SH-SY5Y cell lysate (1:5); serum and plasma samples are recommended to be diluted at least 1:2 with Sample Dilution Buffer prior to testing. The kit is shipped at +4°C, and components are stored at +4°C or −20°C as instructed in the protocol manual.