Fig. 2
Characterization of target peptide standards. a Standard curves for each target analyte peptide over a 9 point dilution showing linearity from 275 fmols to 1 fmol total GP1. An aliquot of the previously quantified eVLP lot ‘A’ (200 fmols/µL SEE at 120 µL dilution) was resuspended 83 µL 40 % acetonitrile, 0.1 % Formic (137.5 fmols/µL) and serially diluted. A 2 µL injection utilizing the described instrument method was run in triplicate for each dilution. R2 values for all four peptides are well within the margin of significance for linearity. Also shown in tabular form are the %CV values for each triplicate XIC measurement for each peptide at each dilution. These data indicate linearity down to 1 fmol with the largest CV% (SVGR—17.3 %) in dilution number ‘8’ of the serially diluted series. b AQUA-SVG peptide signal response for non-deamidated (circle) and deamidated (triangle) peptide. AQUA-SVG peptide was deamidated by incubating 40 pmols at 50 °C/pH 8.0 for 2.5 days while a matching 40 pmol aliquot was stored at −20 °C. A 5-point, twofold serial dilution was performed resulting in a 250–15.6 fmol/µL concentration range for each sample. LC-HRMS was run in triplicate on each dilution and the average counts plotted