Quantification Methods

Liquid Chromatography – Tandem Mass Spectrometry (LC-MS/MS)

The EPC Biomarkers Core has a LC-MS/MS system consisting of a Shimadzu Nexera X2 UHPLC system coupled with an AB Sciex Triple Quad 6500 Mass Spectrometer. By combining ultra-high-performance liquid chromatography (UHPLC) with next generation triple quadrupole technology offered by the AB Sciex 6500, the Biomarkers Core can provide unparalleled sensitivity, precision, and throughput for our clients. The Core primarily uses this LC-MS/MS system for targeted analysis of steroids and other small molecules in nonhuman primate, human, and rodent biological matrices. Both single-plex and multi-plex panels are available (see our assay catalog for more information). The Core also develops LC-MS/MS assays based on the research needs of internal and external investigators (contact us for further discussion).

Enzyme-Linked Immunosorbent Assays (ELISA)

ELISA-based immunoassays enable accurate and precise quantitation of biomarkers such as steroid and protein hormones, amino-acid derivatives, antibodies, and inflammatory markers relevant to various health and disease processes. The Biomarkers Core offers ELISA-based immunoassays for a variety of analytes in biological matrices such as plasma, serum, CSF, urine, feces, saliva, amniotic fluid, tissue extracts, and cell culture supernatant using commercially available ELISA kits at affordable prices (see our assay catalog for more information).

We currently offer over 120 ELISA-based assays.

  • Sex hormones: Testosterone, 17b-Estradiol, Estriol, Progesterone, Androstenedione
  • Stress hormones: Cortisol, Corticosterone, ACTH, CRF
  • Metabolic health biomarkers: Adiponectin, Insulin, Glucose, C-peptide, Glucagon
  • Inflammatory markers: CRP, IL-6, MCP-1, IL-1 beta, TNF-alpha
  • Growth factors: IGF-1, IGF-2, BDNF, FGF21, VEGF
  • Bone markers: P1NP, NTx, PTH, CTX, B-ALP, Osteocalcin
  • Other biomarkers: Oxytocin, Vasopressin, Serotonin (5-HT), Melatonin

The Core houses multiple ELISA plate washers, microplate readers, and other necessary sample processing equipment for hormone extraction from complex biomatrices (feces, saliva). Notably, the Molecular Devices SpectraMax i3x Multi-Mode Detection Platform measures spectral-based absorbance, fluorescent, and luminescent ELISAs. Due to its versatility and reliability when working with complex biomatrices, most of the multi-species analytes offered in the BMC’s immunoassay catalog are performed on this device. The Biomarkers Core also houses a Tecan Infinite M200Pro that is capable of reading colorimetric ELISAs.

Automated enzyme immunoassay and clinical chemistry analyzer

The Biomarkers Core houses a DRG International Hybrid XL, an automated enzyme immunoassay and clinical chemistry analyzer, capable of performing up to 40 tests per hour (up to 17 samples per test). Most commonly requested tests utilizing this instrument in support of human and nonhuman primate studies include tests for 17b-estradiol, progesterone, testosterone, and CRP. This instrument also offers a line of CLIA-certified clinical chemistry tests including tests for HbA1c and insulin as well as a thyroid panel.

Chemiluminescent Immunoassays

Chemiluminescent immunoassays are a variation of the conventional enzyme immunoassays, combining immunochemical reactions with chemiluminescence detection. These assays offer an ultra-sensitive, alternative technology with a broad dynamic range compared to conventional colorimetric ELISAs. The high sensitivity of chemiluminescence immunoassays is ideal for detecting small molecules at low endogenous levels, including measurements of oxytocin and arginine vasopressin (AVP) in human and animal saliva, CSF, and plasma. The Biomarkers Core houses a Tecan Infinite M200Pro that is capable of reading chemiluminescent immunoassays in 6-384 well plate formats.