Fig. 3. Photoaffinity labeling of PNA (1 μg, 50 nM) mixed in cell lysate (100 μg, 0.5 mg mL^–1) using probe 2 (50 nM). (a) SDS-PAGE analysis showing protein band(s) eluted from probe 2. Lane 1: crosslinked-PNA enriched by Gdn-HCl wash, lane 2: negative control experiment with no UV irradiation and no Gdn-HCl wash, lane 3: PNA input as a control. (b) MALDI-TOF MS analysis showing the m/z peaks corresponding to PNA captured by probe 2.