Screening and quantification of high-producing CHO-IGF-E5 clones by spot blot. A: initial screening of all colonies selected by FLSSM and picked by Quixell micromanipulator (A trough EE). std: 20 ng spot of purified IGF-E5 for reference. B: Quantitative spot blot. Top row: purified IGF-E5 standards, numbers indicate amounts spotted in nanograms. Bottom row: 2 best clones isolated by FLSSM (L and Y) and best cell population isolated by classic dilution in wells (4-B4). Duplicates not shown. C: plot of the fluorescence signal obtained by scanning the standard spots using a Typhoon™ scanner, R2 = 0.99.