Magnetic microcarrier beads have a particle size of 1 to 1000 micrometers and include a composite core and a polymer coating that surrounds and encapsulates the core. The composite core includes magnetic particles embedded within an indigestible polymer matrix. The coating is a digestible or indigestible polymer that facilitates cell adhesion to the surface of the beads during cell culture. Magnetic force can be used to agitate the microcarrier beads during cell culture as well as to separate the beads from cultured cells or processed bio-media.