Figure 3. Second HPLC chromatography. The CGRP like molecules obtained from the first HPLC chromatography were further purified on the same HPLC column using a linear gradient from 30 to 60% acetonitrile in 0.1% TFA. The line shows the concentration of acetonitrile in the eluting solvent. Optical density was measured at 226 nm (¨) and the CGRP Iike immunoreactivity (l) determined on an aliquot from each fraction.