Titering" a phage means measuring the concentration of phage in a given solution. Titering Procedure. Rob Philip's Group. - [Read Titering & Propagation of Phage]
When an individual bacterial virus grows in a bacterial host suspended in a top agar lawn, its progeny infect and lyse the surrounding host cells. This causes the appearance of a "hole" or plaque in the otherwise homogeneous bacterial lawn. Since each plaque represents a single virus, the number of viruses in the aliquot added to the plate is equal to the number of plaques which appear. - [Read Titering of Bacterial Viruses Protocol]
This transient transfection protocol for the ecotropic/amphotropic producer line includes instructions for titering and concentration of viral stocks. This procedure gives consistently higher transfection efficiency. - [Read Transient Transfection: Viral Production]