Ortho-phthalic acid from bacterial spores--an artifact.

(CITC), under the conditions of the reported typical experiment (Table 1), contained a total of 4.428 g of protein in a volume of 1,220 ml. The final eluate, in a volume of 274 ml, contained 1.121 g of protein. This represented, in effect, a net removal of 74.7% of proteinaceous material, while effecting a volume concentration of 4.45 X. There was a concomitant increase in the CF antigen titer, from just detectable activity in the undiluted to full CF activity with 1:16 antigen dilution of the concentrate against a serum dilution approximating its control antigen titer (Table 1). Further, it should be noted that no specific CF activity was detectable in the filtrate. The described procedure for the partial purification and concentration of poliovirus has been applied to all three types of poliovirus, and in every instance has produced an improved CF antigen.