Analysis of variance, indicated that there were no significant differences between inhibition of Cts for MS2 and enterovirus RNA for Protocols A, B, and C, but not D, when the amount of enterovirus RNA was equivalent to that of MS2 (P.0.5), whereas there was significantly less inhibition when the 64-fold higher amount of enteroviral RNA was tested for RNA extracted by protocols B, C, and D (P,0.05), but not A (P.0.05).