Fig 1: Apolipoprotein E antibody screening by Western Blot on culture media.HAP1 WT and APOE KO were cultured in serum free media. Media were collected, concentrated, and 30 μg of protein were processed for Western Blot with the indicated Apolipoprotein E antibodies. The Ponceau stained transfers of each blot are shown. Antibody dilutions were chosen according to the recommendations of the antibody supplier. Exceptions were given for antibodies ab1907*,13366**,18254-1-AP, MA5-15852* and 66830-1-Ig* which were titrated to the concentrations listed below, as the signals were too weak when following the supplier’s recommendations. Antibody dilutions used: GTX635889* at 1/200, GTX635891* at 1/200, ab52607** at 1/200, ab51015** at 1/1000, ab1907* at 1/200, 13366** at 1/500, ARP54283 at 1/1000, 701241** at 1/200, MA5-41148** at 1/200, MA5-15852* at 1/200, MAB41441* at 1/200, NB110-60531* at 1/200, 18254-1-AP at 1/200, 66830-1-Ig* at 1/200. Apolipoprotein E predicted band size: 36 kDa. *Monoclonal antibody, **Recombinant antibody.