Membrane-based, sedimentation-assisted plasma separator from whole blood for clinical tests

High sensitivity, point-of-care clinical tests, such as HIV load, require large volumes of plasma.  Centrifugation is widely used for separating plasma from whole blood, but it is not always accessible and can be a limiting factor for point-of-care testing. Current microfluidic systems require extensive blood dilution that adversely affects the limit of detection, which is critical in high sensitivity tests such as viral load detection.

Using size exclusion-based filtration and gravitational sedimentation, researchers in the Bau lab have developed a plasma separator capable of separating plasma from undiluted whole blood within minutes. 

The plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber.  The vertical design of the device avoids membrane clogging and enables the extraction of plasma volumes without a pump and excessive dilution or wash. The device is fabricated from inexpensive, disposable plastics with a footprint no bigger than a dime. Additionally, the device uses no electricity and has no moving parts.

• Low-cost (<$1/test)
• Rapid process
• Easy to administer
• No requirement for electrical power
• Extract large volumes of plasma without clogging
• Self-terminating separation process to prevent hemolysis

• Separate plasma from blood
• Detect viral load when combined with nucleic acid testing on microfluidic chip
• Use in resource-poor regions without trained staff, laboratory facilities, or electricity