A pipette is provided. The pipette includes a body, a piston, and a valve. The body includes a nozzle, a first chamber, a second chamber, and a channel formed in the nozzle. The first chamber is isolated from the second chamber, and the channel is isolated from the first chamber and the second chamber. The piston is mounted to slide within the first chamber and the second chamber so that movement of the piston simultaneously increases a first volume of the first chamber and decreases a second volume of the second chamber. The valve is in communication with the first chamber, the second chamber, the channel, and an exterior of the body to selectively provide a communication between the first chamber and the channel, between the second chamber and the channel, between the first chamber and the exterior of the body, and between the second chamber and the exterior of the body.