An apparatus and method for inoculating a biological substrate with cells include provision for rotating a container in which the substrate and a cell suspension are received about first and second axes of rotation. The apparatus comprises said container, first drive means for rotatably supporting the container about the first axis, and second drive means for rotatably supporting the first drive means about the second axis. The first and second axes of rotation do not lie in the same plane and extend in different directions so that the container revolves around the second axis while the container is rotating about the first axis. The inoculation method utilizes this apparatus.