Fig. 1

^99mTc-SER-4 binds to Sn. Binding studies were performed by incubating ^99mTc-SER-4 and Sn-Fc followed by analysis with radio-HPLC size exclusion chromatography. a ^99mTc-SER-4 elutes at 8 min and 35 s. b ^99mTc-SER-4 was added to Sn-Fc and an elution peak at 7 min and 20 s was observed corresponding to the ^99mTc-SER-4 bound to Sn-Fc. c When ^99mTc-SER-4 was added to Sn-Fc protein in the presence of unlabelled SER-4, no binding was observed and only the ^99mTc-SER-4 elution peak was observed. d ^99mTc-IgG isotype control did not bind to Sn-Fc with a peak elution time similar to ^99mTc-SER-4 of 8 min and 35 s