An apparatus, comprising: a lumen-defining device (120; 220; 320); a housing (101; 201; 301) including a proximal end portion and a distal end portion and defining an inner volume (111; 211; 311) therebetween, the housing (101; 201; 301) having an inlet port (105; 205; /) configured to be removably coupled to the lumen-defining device; characterized by: a fluid reservoir (130; 230; 330) formed at least in part by the housing (101; 201; 301) and configured to transition from a first configuration to a second configuration to create a negative pressure in the fluid reservoir (130; 230; 330), the fluid reservoir (130; 230; 330) configured to receive and sequester a first volume of bodily fluid withdrawn from the patient; a flow control mechanism (140; 240; 340) at least partially disposed in the inner volume (111; 211; 311) of the housing (101; 201; 301) and configured to move relative to the housing (101; 201; 301) between a first configuration and a second configuration, the flow control mechanism (140; 240; 340) defining a fluid flow path between the lumen-defining device and the fluid reservoir (130; 230; 330) in the first configuration; and an actuator (180; /; 380) operably coupled to the flow control mechanism (140; 240; 340) and configured to move the flow control mechanism from the first configuration in which the inlet port is placed in fluid communication with the fluid reservoir (130; 230; 330) such that bodily fluid can flow from the lumen-defining device (120; 220; 320), through the inlet port and the fluid flow path, and to the fluid reservoir in response to the negative pressure, to the second configuration, in which the fluid reservoir is sequestered from the lumen-defining device. a lumen-defining device (120; 220; 320); a housing (101; 201; 301) including a proximal end portion and a distal end portion and defining an inner volume (111; 211; 311) therebetween, the housing (101; 201; 301) having an inlet port (105; 205; /) configured to be removably coupled to the lumen-defining device; characterized by: a fluid reservoir (130; 230; 330) formed at least in part by the housing (101; 201; 301) and configured to transition from a first configuration to a second configuration to create a negative pressure in the fluid reservoir (130; 230; 330), the fluid reservoir (130; 230; 330) configured to receive and sequester a first volume of bodily fluid withdrawn from the patient; a flow control mechanism (140; 240; 340) at least partially disposed in the inner volume (111; 211; 311) of the housing (101; 201; 301) and configured to move relative to the housing (101; 201; 301) between a first configuration and a second configuration, the flow control mechanism (140; 240; 340) defining a fluid flow path between the lumen-defining device and the fluid reservoir (130; 230; 330) in the first configuration; and an actuator (180; /; 380) operably coupled to the flow control mechanism (140; 240; 340) and configured to move the flow control mechanism from the first configuration in which the inlet port is placed in fluid communication with the fluid reservoir (130; 230; 330) such that bodily fluid can flow from the lumen-defining device (120; 220; 320), through the inlet port and the fluid flow path, and to the fluid reservoir in response to the negative pressure, to the second configuration, in which the fluid reservoir is sequestered from the lumen-defining device. a fluid reservoir (130; 230; 330) formed at least in part by the housing (101; 201; 301) and configured to transition from a first configuration to a second configuration to create a negative pressure in the fluid reservoir (130; 230; 330), the fluid reservoir (130; 230; 330) configured to receive and sequester a first volume of bodily fluid withdrawn from the patient; a flow control mechanism (140; 240; 340) at least partially disposed in the inner volume (111; 211; 311) of the housing (101; 201; 301) and configured to move relative to the housing (101; 201; 301) between a first configuration and a second configuration, the flow control mechanism (140; 240; 340) defining a fluid flow path between the lumen-defining device and the fluid reservoir (130; 230; 330) in the first configuration; and an actuator (180; /; 380) operably coupled to the flow control mechanism (140; 240; 340) and configured to move the flow control mechanism from the first configuration in which the inlet port is placed in fluid communication with the fluid reservoir (130; 230; 330) such that bodily fluid can flow from the lumen-defining device (120; 220; 320), through the inlet port and the fluid flow path, and to the fluid reservoir in response to the negative pressure, to the second configuration, in which the fluid reservoir is sequestered from the lumen-defining device.