56. Comparison of MALDI-TOF-MS and HPLC-ESI-MS/MS for Endopeptidase Activity Based Quantification of Anthrax Lethal Factor in Serum
Poster: Tue 6:30-7:30PM
Zsuzsanna Kuklenyik
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We developed a method to diagnose anthrax by endoproteinase activity based quantification of anthrax lethal factor (LF) at attomole/mL levels in serum using isotope dilution MS. We validated our method using MALDI-TOF MS and HPLC-ESI-MS/MS allowing direct comparison of MS platforms on the basis of calibration curve linearity (0.00125-2.5 ng/mL using 200 µL sample), coefficient of variation for QC samples (6–12% for both MS platforms), and measurement of samples from exposed, non-exposed or treated animals (p=0.99 linear correlation and 9% mean difference). This study shows that isotope dilution MALDI-TOF-MS is as robust and precise quantitative platform as HPLC–ESI-MS/MS.