Figure 6.

Labeling studies to ascertain effective probe concentrations (fluorescent gel image shown in grey scale). Probe concentrations were screened using MDA-MB-435 cancer cell extracts (soluble fraction) to identify concentrations that were effective for studies. Concentrations ranging from 200 nM to 1nM were used to label the same amount of the cell extracts with heat-denatured controls performed for each protein concentration. From fluorescence gel imaging results, probe concentrations of approximately 50 µM (lanes 5 and 6) were selected for other labeling studies. Please also see color fluorescence gel scans in Figure S2 of the supplementary information.