title: An ultrasensitive method for the quantitation of active and inactive GLP-1 in human plasma via immunoaffinity LC-MS/MS.
abstract: BACKGROUND
  Measuring endogenous levels of incretin hormones, like GLP-1, is critical in the development of antidiabetic compounds. However, the assays used to measure these molecules often have analytical issues.
  
  
  RESULTS
  We have developed an ultrasensitive, highly-selective immunoaffinity LC-MS/MS (IA LC-MS/MS) assay capable of quantitating endogenous levels of active (7-36 amide) and inactive (9-36 amide) GLP-1 in human plasma. We performed fit-for-purpose validation of the assay by assessing the following assay performance characteristics: inter-assay precision, sensitivity, spike recovery, dilution linearity, absolute recovery, matrix effect, immunoprecipitation efficiency, and food effect.
  
  
  CONCLUSIONS
  We have developed a robust analytical method for the quantitation of endogenous active and inactive GLP-1 in human plasma. In addition, we employed this method to measure the typical changes in GLP-1 levels after food intake. The sensitivity of this assay is better than another LC-MS/MS GLP-1 assay previously reported and many commercially available immunoassays. This important analytical tool could be used to qualify and/or harmonize the different immunoassays used for the quantitation of GLP-1.
authors.affiliation: Clinical Development Laboratory, Merck Research Laboratories, Rahway, NJ, USA.
authors.forename: Derek L
authors.initials: DL
authors.lastname: Chappell
authors.forename: Anita Yh
authors.initials: AY
authors.lastname: Lee
authors.forename: Jose
authors.initials: J
authors.lastname: Castro-Perez
authors.forename: Haihong
authors.initials: H
authors.lastname: Zhou
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Roddy
authors.forename: Michael E
authors.initials: ME
authors.lastname: Lassman
authors.forename: Sudha S
authors.initials: SS
authors.lastname: Shankar
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Yates
authors.forename: Weixun
authors.initials: W
authors.lastname: Wang
authors.forename: Omar F
authors.initials: OF
authors.lastname: Laterza
mesh_terms: D000577:Amides / Q000737:chemistry; D000818:Animals; D000906:Antibodies / Q000737:chemistry; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D004435:Eating / Q000502:physiology; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000592:standards*; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000577:Amides; D000906:Antibodies; D052216:Glucagon-Like Peptide 1