The 96 well base has separate wells which allow you to test different strains in different wells. The trough base doesn’t have separate wells, it’s a tray with open longitudinal rows where inoculated media would flow from side to side on a rocker shaker, which only allows one strain per plate. We sell the MBEC Assay Kits with 96 well bases to 95% of our customers. The trough base is mainly used for plant pathogen strains, where we need larger fluid volume flowing against the pegs.