I'm working with Platinum-E (Plat-E) cells and generating viral particles that carry an insert of interest with a GFP reporter that will be used to infect mouse T cells. I understand that when working with lentiviruses, you would typically infect 293T cells (or a similar cell line) and measure how many cells are positive for GFP to determine your functional viral titer. You would then move on to determine the MOI of your cell type of interest. However, retroviruses produced by Plat-E cells are ecotropic and only infect mouse/rat cells. Thus, I would have to infect a mouse cell line to determine my functional viral titer. Do researchers working with mouse retroviruses typically do this? (Determine functional viral titer by infecting mouse cells). If so, what cell line/type is typically used for determining viral titers. Or is it standard to just jump straight to infecting your cell type of interest?

Thanks in advance for any advice and information!