One of the methodologies described is to solidify the culture medium with an agar gel. As an alternative to solid gels, for their practical convenient, viscous solutions of soluble hydrophilic polymers, methylcellulose (MC), carboxymethyl cellulose (CMC), can be employed. If strong cytopathogenic effects (CPE) are induced cells in plaques are lysed and plaques can be visualized by staining of the residual intact cells [7, 8].