LC-MS Method Development

Chiral Analysis of Amino Acids

We developed a RPLC-MS/MS method to resolve and quantify the 20 common proteinogenic amino acid D- and L- stereoisomers using Marfey's derivatization technique. We then used the method to study these amino acids in bacterial extract. This method can be used to analyze these amino acid isomers in different biological matrix with adjustments.

MRM MS chromatogram depicting 20 proteinogenic amino acid D- and L- stereoisomers.

(Ref.: Ayon et al. JASMS 2018)

DNA Oxidative Enzyme Activity Analysis

We developed several RPLC-MS/MS methods for analyzing normal and oxidized DNA nucleosides to study a DNA oxidizing enzyme (TET2).

SDS-PAGE analysis of purified TET2 dioxygenase from E. coli BL21 (DE3) cells.

(Ref.: Bhattacharya et al. JoVE 2018)

MRM MS chromatogram for the normal and oxidized nucleosides in positive mode.

(Ref.: Bhattacharya et al. JoVE 2018)

MRM MS chromatograms of eight different nucleosides in the ion-switching mode. Period 1: positive mode (1–6 min); period 2: negative mode (6–11 min); period 3: positive mode (11–23 min).

(Ref.: Dey et al. BMP 2020)