A device and method for removing gas from a mixture of biomaterials includes a vacuum pump movably positioned within a cavity of a syringe at least partially defining a vacuum chamber. The vacuum pump has a pump body with proximal and distal portions, a stopper connected to the distal portion, and a flow channel. The stopper includes an inlet, and the pump body includes a port. The flow channel extends from the inlet to the port and is in fluid communication with the vacuum chamber. A first valve is positioned within the flow channel between the inlet and the port. The first valve is operable to open and close the flow channel for selectively connecting a vacuum to the vacuum chamber such that gas is withdrawn from mixture of biomaterials within the vacuum chamber.