Figure 7. Radiochemical stability of [^99mTc][Tc(CO)3]⁺-labeled (in PBS) sequences after exposure to human serum for 24 h.

Sequence categories and color coding are as for SI Figure S3. Only His-free peptide spots and peptide-free spots (white symbols) lost a significant fraction of their radioactivity. Similar data are shown in Supporting Information for exposure to serum for 1 and 2 h (Figure S20), and for incubation with PBS (Figure S18) and histidine and cysteine solution (Figure S22), along with a legend showing color coding of peptide categories and the images used to obtain these data (Figures S19, S17, S21).