AIMS: To evaluate the performances of commercially available glucagon-like peptide-1 (GLP-1) assays and the implications for clinical studies. METHODS: Known concentrations (5-300 pmol/l) of synthetic GLP-1 isoforms (GLP-1 1-36NH2, 7-36NH2, 9-36NH2, 1-37, 7-37 and 9-37) were added to the matrix (assay buffer) supplied with 10 different kits and to human plasma, and recoveries were determined. Assays yielding meaningful results were analysed for precision and sensitivity by repeated analysis and ability to discriminate low concentrations. Endogenous GLP-1 levels in clinical samples were assessed using three commercial kits. RESULTS: The USCN LIFE assay detected none of the GLP-1 isoforms. The active GLP-1 enzyme-linked immunosorbent assays (ELISAs) from Millipore and DRG appeared identical and were specific for intact GLP-1 in buffer and plasma. The Meso Scale Discovery (MSD) total GLP-1 kit detected all six GLP-1 isoforms, although recovery of non-active forms was incomplete, especially in plasma. Millipore total GLP-1 ELISA kit detected all isoforms in buffer, but mainly amidated forms in plasma. The Alpco, Phoenix and Bio-Rad kits detected only amidated GLP-1, but the Alpco kit had a limited measurement range (30 pmol/l), the Phoenix kit had incomplete recovery in plasma and the Bio-Rad kit was insensitive (detection limit in plasma 40 pmol/l). The pattern of postprandial GLP-1 responses in clinical samples was similar between the kits tested, but the absolute concentrations measured varied. CONCLUSIONS: The specificity and sensitivity of commercially available kits for the analysis of GLP-1 levels vary considerably. This should be taken into account when selecting which assay to use and when comparing data from different studies.
AIMS: To evaluate the performances of commercially available glucagon-like peptide-1 (GLP-1) assays and the implications for clinical studies. METHODS: Known concentrations (5-300 pmol/l) of synthetic GLP-1 isoforms (GLP-1 1-36NH2, 7-36NH2, 9-36NH2, 1-37, 7-37 and 9-37) were added to the matrix (assay buffer) supplied with 10 different kits and to human plasma, and recoveries were determined. Assays yielding meaningful results were analysed for precision and sensitivity by repeated analysis and ability to discriminate low concentrations. Endogenous GLP-1 levels in clinical samples were assessed using three commercial kits. RESULTS: The USCN LIFE assay detected none of the GLP-1 isoforms. The active GLP-1 enzyme-linked immunosorbent assays (ELISAs) from Millipore and DRG appeared identical and were specific for intact GLP-1 in buffer and plasma. The Meso Scale Discovery (MSD) total GLP-1 kit detected all six GLP-1 isoforms, although recovery of non-active forms was incomplete, especially in plasma. Millipore total GLP-1 ELISA kit detected all isoforms in buffer, but mainly amidated forms in plasma. The Alpco, Phoenix and Bio-Rad kits detected only amidated GLP-1, but the Alpco kit had a limited measurement range (30 pmol/l), the Phoenix kit had incomplete recovery in plasma and the Bio-Rad kit was insensitive (detection limit in plasma 40 pmol/l). The pattern of postprandial GLP-1 responses in clinical samples was similar between the kits tested, but the absolute concentrations measured varied. CONCLUSIONS: The specificity and sensitivity of commercially available kits for the analysis of GLP-1 levels vary considerably. This should be taken into account when selecting which assay to use and when comparing data from different studies.
Authors: Dariush Elahi; Dennis A Ruff; Olga D Carlson; Graydon S Meneilly; Joel F Habener; Josephine M Egan Journal: Endocr Res Date: 2015-07-17 Impact factor: 1.720
Authors: Johanne A Windeløv; Nicolai J Wewer Albrechtsen; Rune E Kuhre; Sara L Jepsen; Daniel Hornburg; Jens Pedersen; Elisa P Jensen; Katrine D Galsgaard; Marie Winther-Sørensen; Anne Ørgaard; Carolyn F Deacon; Matthias Mann; Hannelouise Kissow; Bolette Hartmann; Jens J Holst Journal: Diabetologia Date: 2017-07-01 Impact factor: 10.122
Authors: Robert E Steinert; Christine Feinle-Bisset; Lori Asarian; Michael Horowitz; Christoph Beglinger; Nori Geary Journal: Physiol Rev Date: 2017-01 Impact factor: 37.312
Authors: Sara L Jepsen; Kaare V Grunddal; Nicolai J Wewer Albrechtsen; Maja S Engelstoft; Maria B N Gabe; Elisa P Jensen; Cathrine Ørskov; Steen S Poulsen; Mette M Rosenkilde; Jens Pedersen; Fiona M Gribble; Frank Reimann; Carolyn F Deacon; Thue W Schwartz; Andreas D Christ; Rainer E Martin; Jens J Holst Journal: Am J Physiol Endocrinol Metab Date: 2019-09-10 Impact factor: 4.310
Authors: Sara E Stinson; Anna E Jonsson; Morten A V Lund; Christine Frithioff-Bøjsøe; Louise Aas Holm; Oluf Pedersen; Lars Ängquist; Thorkild I A Sørensen; Jens J Holst; Michael Christiansen; Jens-Christian Holm; Bolette Hartmann; Torben Hansen Journal: J Clin Endocrinol Metab Date: 2021-05-13 Impact factor: 5.958