Table 7.

Comparison of Immunoassay Kits Measuring NPY levels.

Assay	Source	Sensitivity	Specificity
RIA	Euro Diagnostica-ALPCO Diagnostics, Salem, NH	~12.81 pg/ml	<0.1% cross-reactivity with NPY22-36, peptide YY, pancreatic polypeptide, and other neuropeptides.
RIA	Allen et al. (1991)	20 pg/mL with intra- and inter-assay coefficients of variation of 8% and 10%, respectively.	Percent binding of NPY and NPY 2–36 to [NPY]-α-globulin 3-5 was 100% and 100%, respectively.
EIA	RayBiotech, Norcross, GA	3 ng/ml or 3000 pg/ml (Reijnen et al., 2018)	Detects human, mouse, and rat active NPY (1–36)a
EIA	EMD Millipore Corporation, Billerica, MA	2 pg/ml using a 50 μL sample sizeb	Human, Rat NPY: 100%, NPY 2–36: 67%, NPY 3–36: 68%, NPY (free acid): 6%, NPY 13–36: 8%, (Leu31, Pro34) Human, Rat NPY: 41%, Porcine NPY: 44%, Porcine NPY 3–36: 41%. Pancreatic polypeptide and other human peptides: 0%b

NPY: Neuropeptide Y; RIA: Radioimmunoassay; EIA: Enzyme Immunoassay.

^ahttps://www.raybiotech.com/files/manual/EIA/EIA-NPY.pdf.

^bhttp://www.emdmillipore.com/US/en/product/Human-Neuropeptide-Y-NPY-ELISA,MM_NF-EZHNPY-25K#anchor_PR