To make sure these reservoirs arrive sterile, they've been irradiated, individually bagged, and marked with a lot number. Use them to hold reagents and samples for easy access during pipetting. A V-shaped bottom helps you collect samples as your liquid starts to run low. All have molded graduation marks, so you can gauge how much liquid is inside. There’s a pour spout on each corner for discarding excess liquid. These reservoirs cannot be autoclaved or reused.