Rat Chromogranin A ELISA Kit

A sandwich ELISA in a double antibody format from Assay Genie, designed for the quantification of chromogranin A in rat samples. It is reactive with rat and accepts serum, plasma, cell culture supernatant, cell or tissue lysate, and other liquid sample types. Detection is colorimetric, with absorbance measured at 450 nm after TMB substrate development. Chromogranin A is described as a key protein involved in regulating hormone secretion and neurotransmitter release, used as a biomarker in studies of neuroendocrine functions and disorders such as neuroendocrine tumours, cardiovascular diseases and stress-related conditions.

The assay has a sensitivity of 0.469 mIU/mL and a working range of 0.781–50 mIU/mL (20 ng = 50 mIU). Linearity has been validated in serum (n = 5) at 1:2, 1:4 and 1:8 dilutions with ranges of 85–102%, 85–101% and 86–99% respectively; in EDTA plasma (n = 5) at 85–104%, 87–101% and 81–92%; and in heparin plasma (n = 5) at 86–104%, 82–101% and 82–91%. Spike-and-recovery testing (n = 5) returned average values of 94% for serum (range 88–104%), 94% for EDTA plasma (range 89–102%) and 95% for heparin plasma (range 85–105%).

The protocol uses a pre-coated microplate. After equilibrating reagents to room temperature, samples and standards are incubated at 37°C for 90 minutes, followed by a biotin-labelled detection antibody at 37°C for 60 minutes, HRP-streptavidin SABC at 37°C for 30 minutes, and TMB substrate developed in the dark for 10–20 minutes. The reaction is stopped and absorbance read at 450 nm. Serum is prepared by clotting and centrifugation at 1000 × g for 20 minutes; plasma is collected using anticoagulant tubes and centrifuged at 1000 × g for 15 minutes at 2–8°C. The kit should be stored at 2-8°C and remains stable for 12 months under those conditions.