Blood collection device that sequesters an initial collected portion

Various embodiments of the present disclosure describe a diversion device that traps an initial flow of blood in a diversion chamber of the diversion device. The diversion device comprises a housing having an inlet conduit and an outlet conduit; a diversion chamber that comprises a flow path defined by a channel or series of channels that terminate in a diversion chamber valve; a collected sample valve; and bypass flow chamber positioned within the housing, wherein the collected sample valve is configured to permit subsequent flow of fluid to enter the bypass flow chamber, and the bypass flow chamber is configured to permit the subsequent flow of fluid to exit the diversion device. The diversion chamber valve allows air, but not blood, to flow through it.