Emission spectral characteristics of Th-T binding with rSMD IBs harvested at 1, 3, 5 and 20 h post induction. A. Th-T spectra with IBs collected under controlled pH conditions. B. Th-T spectra with IBs recovered from uncontrolled pH cultures. An emission spectrum of Th-T alone is shown in A as a grey lane near zero. Concentrations of Th-T and IBs used for assay were 75 MM and 50 μg/mL respectively.