Quantification of unlabeled peptides using SIL calibration curve

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Quantification of unlabeled peptides using SIL calibration curve david schmidt  2020-06-08
 

Hi,

once again thanks for this great piece of software!

We are trying to quantify light (native) peptides using their isotope-labeled synthetic counterparts as standards. In contrast to the example in the "Absolute Quantification" tutorial, our calibration curve is generated with heavy peptides in a comparable matrix (and not with different light/heavy ratios). We do, however, spike a fixed concentration of heavy peptides into each sample to compensate for recovery differences.

The goal is to calculate the concentration of the light peptides using the labeled peptide's calibration curve and then to normalize that concentration value to the recovery (measured conc. heavy/spiked conc. heavy). My problem is, how to apply the heavy peptide-based calibration curve for the quantification of light peptides. Is there a way to specify the "internal standard type" separately for the calibration curve and the samples?

Thank you,

David