Paf ah activity assay kit

Detailed information has been previously published [16 (link)]. Briefly, blood samples were collected following an overnight fast of at least 12 h, and the levels of fasting triglycerides; total-, high-density lipoprotein (HDL)-, and low-density lipoprotein (LDL)-cholesterol; apolipoprotein (apo) A-I and B; glucose; insulin; and high-sensitivity C-reactive protein (hs-CRP) were measured. The activity of Lp-PLA₂, also known as platelet-activating factor acetylhydrolase (PAF-AH), was measured using a PAF-AH activity assay kit (Biovision, Milpitas, CA). The resulting change in absorbance was immediately read at 412 nm for 30 min at room temperature using a VERSAmax microplate reader in kinetic mode (Molecular Devices, Sunnyvale, CA). Lp-PLA₂ activity was expressed in nmol of PAF hydrolyzed per min per mL of serum. Plasma oxidized LDL (ox-LDL) was measured using an enzyme immunoassay (Mercodia AB, Uppsala, Sweden). The resulting color reaction was monitored at 450 nm with a Wallac 1420 Victor² multilabel counter (PerkinElmer Life Sciences, Boston, MA).

The activity of Lp‐PLA2, also known as platelet‐activating factor acetylhydrolase (PAF‐AH) was measured at the Biomarker Core Laboratory of the Atlanta VA, using a PAF‐AH activity assay kit, which produces results based on a colorimetric shift (Biovision, Milpitas, CA), according to the manufacturer's instructions. Performance characteristics for the Lp‐PLA2 test were established using the enzymatic method Beckman Coulter AU400, a dual monoclonal antibody immunoassay standardized to recombinant Lp‐PLA2 (PLAC test, diaDexus, Inc) (Dada et al. 2002). To assess intra‐assay precision and total variability for Lp‐PLA2 measurement, five human plasma samples and two buffer controls with Lp‐PLA2 activity distributed throughout the calibration range of the assay were measured in 40 separate assays to determine the intra‐assay coefficient of variation (Le et al. 2015).

The plasma ox-LDL level was assessed using an enzyme immunoassay (Mercodia AB, Uppsala, Sweden). The resulting change was monitored at 450 nm using a Wallac 1420 Victor² Multi-Label Counter (PerkinElmer Life Sciences, Boston, MA, USA). Lp-PLA₂ is also called platelet-activating factor acetylhydrolase (PAF-AH). The Lp-PLA₂ activity was measured using a PAF-AH Activity Assay Kit (Biovision, Milpitas, CA, USA), which produces results based on a colorimetric shift, following the manufacturer’s instructions. The color reaction results were immediately measured at 412 nm using a VERSAmax Microplate Reader (Molecular Devices, Sunnyvale, CA, USA) in kinetic mode.