Fig. 3From: ORF1a of highly pathogenic PRRS attenuated vaccine virus plays a key role in neutralizing antibody induction in piglets and virus neutralization in vitroIdentification of the rescued virus based on CPE. a-h Infection of MARC-145 cells with rHuN4-F112, rCH-1R, rHuN4-F112-C1a, rHuN4-F112-C1b, rHuN4-F112-C27, rCH-1R-H1a, rCH-1R-H1b and rCH-1R-H27, respectively. i Uninfected negative control MARC-145 cells. Magnification, 400 ×Back to article page