Fig. 2: Feasibility of using ΦSMD and stable isotope isobarically labeled cell culture (SIILCC).

a An example of reporter ion isotopologues ± ΦSDM. Insufficient resolving power results in reporter ion coalescence (top, for illustrative purposes, data was collected in profile mode) using the conventional eFT mode of MS data acquisition, while the ΦSMD-based approach allowed for resolving closely spaced reporter ions. b Proportional heat response was not observed in MEK2 reporter ion intensities acquired with conventional eFT MS data acquisition at 15 K resolution setting compared to MEK2 reporter ion intensities acquired at 15 K resolution setting using ΦSDM. c MEK2 melting curves acquired with and without ΦSDM show differences in T_m and melting curve profiles. d MEK2 melting curve from the “Meltome” database as a reference melting curve. e Median reporter ion intensities acquired with and without SIILCC demonstrating the negligible effect of the SIILCC carrier channel on the performance of TSA measurements. f Median fitted protein level melting curves with and without SIILCC showing high similarity. g MEK2 reporter ion intensities acquired with and without SIILCC. h MEK2 fitted protein level melting curves with and without SIILCC demonstrating high similarity in curve profiles and T_m values. The error bars represent the standard deviation (n = 2 for e and g, and n = 3 for b, c, f, and h).