Labeling of live cells bearing two bioorthogonal chemical reporters. Jurkat cells were incubated with combinations of Ac4ManLev (50 μM), Ac4GalNAz (150 μM), and no sugar for 2 d, followed by labeling with both 1 and biotin hydrazide at pH 6.5 and, subsequently, with FITC-avidin. The fluorescence of each sample was measured by flow cytometry. x-axis: FITC fluorescence; y-axis: Cy5.5 fluorescence. (A) – Ac4ManLev, + Ac4GalNAz. (B) + Ac4ManLev, + Ac4GalNAz. (C) – Ac4ManLev, – Ac4GalNAz. (D) + Ac4ManLev, – Ac4GalNAz.