In a paper published in Multiple Sclerosis’ January issue (submitted Nov 2004), Ross & coworkers compare our protein G affinity-chromatography RIA for IFN-beta BAb with a commercially available solid-phase enzyme immunoassay (e.g. ELISA) and, in addition, CPE assays for IFN-beta NAb using both fixed amount and serially diluted sera (10-to-1 LU/ml, Kawade-type)