A simple gravity-fed perfusion system constructed from common laboratory supplies. Perfusate is added to the reservoir (e.g., a 60-cc syringe), and the system is primed with a 3-cc syringe to remove any air. The flow of perfusate is monitored by observing drip rates in the air trap (a second 3-cc syringe), and the rate is controlled by a thumb-wheel flow regulator taken from a standard medical intravenous set. A vacuum flask serves as the waste container.