The time span of CPE after infection with poliovirus was more than 48h. The viruses released to supernatant at the early stage of infection were unstable, and the infectious liters of them decreased by more than 0.25Log TCID50 every 24h.

• 细胞感染脊髓灰质炎病毒后出现细胞病变时间跨度大于48h，早期从病变细胞释放出的病毒在培养上清中不稳定，感染性滴度每24h降低0.；25 LogTCID50以上。