High sensitivity elisa kit

hPL was run using ELISA kits purchased from IBL-America (Minneapolis, MN), with an inter-assay CV of 17%. Concentrations were too low at 10 weeks to be reliably detected and thus only 32 week samples were assayed. PGH was run using ELISA kits purchased from MyBiosource.com, with an inter-assay CV of 14% (assayed in both 10 and 32 week gestation samples). IGF-1 was analyzed using an automated chemiluminescent immunoassay system (Immulite 1000, Siemens Diagnostics). Inter-assay CV was 9.5% for pooled plasma run as a quality control. Insulin and IGFBP-1 were each assessed using a high sensitivity ELISA kit (Alpco Diagnostics, Salem NH). Insulin had an inter-assay CV of 6.2% for a pooled plasma sample; IGFBP-1 had an inter-assay CV of 4.6% for a quality control sample provided by the manufacturer. Lab technicians were blinded to supplementation group.

Systemic inflammation was measured by serum levels of TNF-α, interleukin-6 (IL-6), and C-reactive protein (CRP) through blood sample analysis. TNF-α was analyzed using the high-sensitivity ELISA kit (Quantikine HSTA00C, R&D Systems, Minneapolis, MN). IL-6 was assayed using the high-sensitivity ELISA kit (Quantikine HS600B, R&D Systems). CRP was assayed with the high-sensitivity ELISA kit (030–9710 s, ALPCO, Windham, NH).