Plates are labeled with alpha-numeric markings for easy identification of individual wells.Each well has a raised rim which nests into the rings on the single direction lid to reduce evaporation and limit the risk of cross contamination.Lids have a stacking feature for added stability when handling tall stacks of plates.4 well plate is a smaller footprint option which offers well size similar to that of a 24 well plate, but has expanded well spacing to reduce cross contamination.