The Biostat® I modular bioprocess system, an enhanced, entry-level research tool, is capable of running one or two experiments simultaneously. Low maintenance single-walled spinner flasks or stirred-tanks may be used, which increases the versatility of the system. Integrated measurement amplifiers for temperature, pH, pO2, and foam/level for each vessel make upgrades from single units to twins simple. Process control may incorporate rotameters, gas-mixing valves, mass-flow controllers, pumps and motor controllers, as needed.