4.4. Analytical Size Exclusion Chromatography
Analytical SEC was performed on a 24 mL Superose® 6 10/300 GL column (GE Healthcare) using an ÄKTA Explorer 10 system operated at a flow rate of 0.5 mL/min with PBS as the running buffer. To determine the apparent molecular size, purified PAS-Tα1 or PAS-Tα1 (100 µL) was applied to the column and the elution volume was used for linear interpolation from a half-logarithmic calibration line obtained using the reference proteins thyroglobulin (octamer), thyroglobulin (tetramer), apoferritin, β-amylase, alcohol dehydrogenase (tetramer), transferrin, ovalbumin, and carboanhydrase as well as blue dextran (all from Merck, Darmstadt, Germany).