Full-length HTT-Q138 purification and standard curve for HTT-ELISA assay. Panel A, Gel coomassie staining of samples from the HTT-Q138 purification process (lane 1: molecular weight standard; lane 2: 30 μg RL1 cell lysate before induction; lane 3: 30 μg RL1 cell lysate 24 h post induction; lane 4: anti-FLAG affinity gel flow trough; lane 5–6: gel washes; lane 7–9: 5 μL of eluted fractions). Panel B, Western blot stained with anti-FLAG (lanes sequence as in panel A). Panel C, HTT-ELISA assay standard curve displays absorbance calibration values in duplicates individually. Curve showed is a representative example of multiple assays.