This affinity purified antibody has been tested for use in ELISA and by western blot. Specific conditions for reactivity should be optimized by the end user. Although the predicted MW of FBOX9 isoform 1 is 52 kDa, antibody reactivity against MCF7 whole cell lysates shows a predominant band at 100 kDa. This band is believed to be FBOX9 and the higher apparent MW may be due to its association with other proteins. Isoforms 1, 2 and 3 have reported molecular weights of 52.3, 51.1 and 47.3 kDa, respectively.