Effect of p3-Alc
extraction from serum and plasma on the quantification of p3-Alc
with sELISA. A. Quantification of p3-Alcα35 peptide in human serum (left) and plasma (right) without extraction. Synthetic p3-Alcα35 peptide was dissolved in human serum and plasma and the samples in the indicated concentrations, and samples were assayed by ELISA alongside samples in which standard p3-Alcα35 peptide was dissolved in buffer A (closed diamonds in each respective panel). The p3-Alcα35 peptide was added to undiluted serum or plasma [closed squares], or to serum or plasma diluted 2-fold [open triangles] or 4-fold [open circles] with buffer A. B. p3-Alcα35 peptide was added to undiluted serum (left) or plasma (right), and extracted using the procedure described in "Materials and Methods". Extracted samples (open squares in panel B) were also examined alongside a standard p3-Alcα35 peptide dissolved in buffer A (closed diamonds). Endogenous p3-Alcα levels in serum and plasma (no addition of synthetic p3-Alcα) were subtracted in order to determine the specific curve for quantifying levels of synthetic p3-Alcα.