The research proposed is aimed at the eventual development of a unique microcarrier bead for cell culture applications that combines the best features of SoloHill~s styrene-based microcarrier (rapid spreading, rapid entry into the proliferation cycle and ease of cell removal) and a Swedish made dextran-based microcarrier. This unique bead is comprised of a swellable, copolymer with a trimethylamine (TMA) surface. Preliminary findings (see figures) show (a) cell attachment is rapid, (b) cell spreading and proliferation is good, (c) cell harvesting takes place in a short period of time with exceptional cell viability and (d) cell visibility is good. The combination of characteristics [(a) through (d)] has not been achieved today with any microcarrier beads. Specific Aim I. To examine the ability of copolymer/TMA microcarriers (either alone or coated with either porcine collagen or ProNectin-F) to support cell attachment, spreading and growth with seven different commercially-important cells and to examine cell recovery from these substrates. Specific Aim II. To assess production of infectious bovine rhinotracheitis virus (IBR) by MDBK cells grown on copolymer/TMA microcarriers. Successful accomplishment of these two aims will demonstrate feasibility for producing a commercially useful biological on this unique, new bead.