A mains electricity (AC-powered) appliance designed for the storage of laboratory products, specimens, cultures, reagents and other laboratory materials both at refrigerated temperatures (typically 1° to 6° Celsius) and in a frozen state (typically -18° to -30° Celsius). It includes refrigeration and freezing compartments with internal shelving, controls, sensors and alarms to signal out-of-range temperatures and power failures; its interior is typically corrosion-resistant to minimize the risk of adulteration, contamination, and/or corrosion of contents. The refrigeration unit is typically equipped with a safety thermostat to protect the products from freezing.