Given that the affinity of the membranes was such that they might retain more than 99% of the virus, it occurred to me that this might afford a basis for concentration of viruses from fluid suspension, assuming that means could be found to elute the virus from the filter matrix. We used an eluent of 30% agamma chicken serum in phosphate-buffered saline (PBS) and reported a 50% probability of detecting coxsackievirus A9 (CA9) in tap water at the level of 2 PFU per liter (Cliver 1967b) . These results were summarized at a 1965 symposium (Transmission of Viruses by the Water Route) convened by Dr. Gerald Berg in Cincinnati and hosted by the Federal Water Pollution Control Administration, falling within the US Department of Interior. I coined the term ''membrane chromatography'' for this process: I had done column chromatography previously, and I envisioned the membrane as a cylinder with an extreme height-to-diameter ratio. More recently, ''virusadsorption-elution'' has been contracted to ''viradel.'' Advance notice of our study resulted in several discussants mentioning experiments that basically corroborated our report. At that point in my career, I did not realize that publication in a proceedings volume was not equivalent to publication in a refereed journal; worse yet, the proceedings volume did not appear until 1967 (Berg 1967) . I also suffered from inability to think big-since that time, many innovations have been added, some of which have not stood the test of time, commercial versions have been developed, and adsorption-elution has become the basis for large-scale official water testing methods of the US Environmental Protection Agency (EPA-EPA 2001) . I had little input to these developments.