Adhesive EPTFE Vent For Blood Collection / Plasma Separation Device Packaging

The adhesive ePTFE vent for blood collection and plasma separation device packaging is a sterile barrier and gas exchange component engineered for the complex blood processing consumables that are central to modern transfusion and diagnostic medicine. This vent integrates a medical-grade, hydrophobic ePTFE membrane with a validated, blood-compatible adhesive carrier, designed for direct application to the housings of blood collection tubes, plasma separation cards, microfluidic blood analysis cartridges, and apheresis kit packaging. It provides a sterile airway that enables the precise pressure equalization required for capillary-driven microfluidic blood flow and for the vacuum draw of evacuated blood collection tubes. The vent maintains an absolute bacterial and viral barrier, protecting the blood sample from environmental contamination and protecting healthcare workers from exposure to bloodborne pathogens. It also prevents liquid blood or plasma from leaking, ensuring that the hazardous sample is fully contained.

Blood collection and plasma separation devices operate on precise pressure differentials. An evacuated blood collection tube (e.g., ) relies on a pre-set internal vacuum to draw the exact volume of blood from the vein. Any leakage in the closure that allows air to enter over time will degrade this vacuum, resulting in an under-filled tube and an incorrect blood-to-additive ratio that compromises laboratory test results. Plasma separation cards and microfluidic blood analysis cartridges use capillary action, requiring atmospheric pressure to drive the blood through the micro-channels. If the device is sealed without a vent, the advancing blood column compresses the trapped air, creating back-pressure that stops the flow. A vent is needed to allow the air to escape. However, any vent on a blood-containing device must be a complete biological barrier, preventing the escape of potentially infectious blood (hepatitis B, C, HIV) and preventing the ingress of bacteria that could contaminate the sample or the sterility of the device interior.

The adhesive ePTFE vent provides a sterile, hydrophobic airway directly on the blood collection or separation device. For plasma separation cards, applied over the air exit port, the vent allows the displaced air to escape as the blood fills the microfluidic channels, ensuring complete, uniform filling without back-pressure. For evacuated tubes, the vent can be integrated into the closure to provide a redundant sterile barrier behind the primary rubber stopper. The 0.2-micron hydrophobic membrane is an absolute barrier to bacteria, viruses, and liquid blood. The membrane will not allow blood—even plasma, which has lower surface tension—to leak out, even under the pressure of centrifugation or if the device is dropped. The adhesive bond is validated to withstand the centrifugal forces of laboratory centrifuges (up to 5,000 g) and the temperature extremes of refrigerated storage and transport.

• Evacuated blood collection tube closure vents
• Plasma separation card and dried blood spot (DBS) card vents
• Microfluidic point-of-care blood analysis cartridges
• Apheresis collection kit packaging vents
• Blood culture bottle vents
• Centrifugal plasma separation device vents

The vent is applied over a precision port on the blood collection tube cap, separation card, or microfluidic cartridge. For a microfluidic device, as the blood sample is introduced and flows through the channels by capillary action, the displaced air escapes through the ePTFE membrane. This prevents any back-pressure buildup, allowing the blood to fill the channels completely and uniformly. For an evacuated tube, the vent provides a secondary sterile barrier behind the primary stopper. If the stopper is accidentally compromised, the vent prevents bacterial ingress. The hydrophobic/oleophobic membrane ensures that liquid blood, plasma, or serum cannot penetrate and leak, even during centrifugation. The adhesive maintains its bond to the plastic or glass substrate throughout the device's use.

1. Identify the blood collection or separation device and the specific gas exchange requirement: vacuum maintenance, capillary flow venting, or centrifuge pressure relief.
2. Determine the required biological barrier level: bacteria, virus, and bloodborne pathogen containment per OSHA and CLSI guidelines.
3. Select the adhesive for the device substrate (PP, PET, glass, etc.) and validate centrifuge stability if applicable.
4. Test the complete device: blood flow and filling performance, leak testing with blood or simulated blood, and biological barrier challenge testing.
5. Conduct hemolysis and biocompatibility testing to ensure the vent materials do not affect blood sample integrity.

• Q: Will the vent cause hemolysis of the blood sample during centrifugation?
  A: The vent is biocompatible and non-hemolytic. It does not mechanically damage blood cells. Hemolysis testing according to ASTM F756 is part of our standard biocompatibility validation.
• Q: Can blood plasma—which has a lower surface tension than whole blood—leak through the hydrophobic membrane?
  A: The membrane includes an oleophobic treatment that specifically resists wetting by plasma and serum. The water entry pressure is validated for plasma as well as whole blood.
• Q: Does the vent affect the vacuum draw of an evacuated blood collection tube over its shelf life?
  A: The vent is a passive sterile barrier and does not contribute to vacuum decay. The vacuum retention is a function of the primary stopper seal. The vent provides a secondary safety barrier without impacting vacuum performance.
• Q: Can the vent be used in devices that undergo steam sterilization after assembly?
  A: The adhesive vent is typically used for devices sterilized by gamma or EtO. For steam-sterilized devices, we offer weldable vent carriers that withstand autoclave temperatures.
• Q: Is the vent compatible with the additives in blood collection tubes (e.g., EDTA, heparin, citrate)?
  A: Yes, the ePTFE membrane and adhesive are chemically inert to common blood anticoagulants and preservatives. We recommend a compatibility test with your specific additive formulation.