A container is provided for cell growth by artificial cultivation of selected biological material in a growth liquid for use in an oscillating incubator. The container has a circular bottom with rounded corners joining a sidewall that is inclined at an angle toward a longitudinal axis of the container to define a container volume. The bottom has six equally spaced baffles extending inward from the corners and upward toward a large diameter opening of the container centered on the longitudinal axis. The baffles have a triangular cross-sectional shape with an included angle of about 28 40.degree., and a height measured parallel to the longitudinal axis of about 15 25% of the usable container volume. The baffles end before the longitudinal axis. The container and baffles are blow molded of a polymer suitable for blow molding. An air permeable filter is placed over the container opening, with the filter having an adhesive on one side to stick to the container. A finger tab on the periphery of the filter helps position and remove the filter.