Cap with venting plug for biological fluid collection device
A cap with a venting plug for a biological fluid collection device is disclosed. The venting plug allows air to pass therethrough and prevents a blood sample from passing therethrough. In one embodiment, the venting plug is a porous plug. In one embodiment, the cap includes a venting plug including a carboxymethylcellulose additive. A cap that limits analyte bias due to the interaction of plasma ions with the carboxymethylcellulose by reducing the contact area between the blood and the carboxymethylcellulose additive, e.g., decreasing radius, is also disclosed.
1 . A biological fluid collection device, comprising:
a blood collection tube;
a stopper sealing an opening in the blood collection tube;
a collection module disposed within the blood collection tube, the collection module including a first end attached to the stopper, a second end opposite the first end and positioned within the blood collection tube, and a passageway extending therebetween; and
a cap body attached to the second end of the collection module within the blood collection tube, the cap body defining:
a plug portion at a front end of the cap body configured to reside within the passageway of the collection module,
a flange portion at a back end of the cap body, wherein the flange portion has an outer diameter greater than an outer diameter of the plug portion and is configured to abut the second end of the collection module,
a first chamber having a first diameter,
a second chamber having a second diameter, and
a third chamber having a third diameter, the second chamber disposed between the first chamber and the third chamber, wherein the first chamber includes a first opening at the front end of the cap body and the third chamber includes an opening at the back end of the cap body, wherein the first chamber is disposed within the plug portion, the second chamber is disposed within at least a portion of both the plug portion and the flange portion, and the third chamber is disposed within the flange portion; and
a venting plug disposed in the third chamber, the venting plug comprising a carboxymethylcellulose additive, wherein the venting plug is configured to permit air to flow from the passageway, through the cap body, and into the blood collection tube.
2 . The biological fluid collection device of claim 1 , wherein the second diameter is less than the first diameter, and wherein the second diameter is less than the third diameter.
3 . The biological fluid collection device of claim 1 , wherein the first diameter is less than the third diameter.
4 . The biological fluid collection device of claim 1 , wherein the first diameter is 1.016 mm, the second diameter is 0.4 mm, and the third diameter is 1.5 mm.
5 . The biological fluid collection device of claim 1 , wherein a length of the second chamber is 1.6 mm and a length of the third chamber is 3.5 mm.
6 . The biological fluid collection device of claim 1 , wherein the venting plug prevents a blood sample from passing therethrough, and wherein the cap body defines an air flow path from the first chamber to the second chamber, through the venting plug, and exiting the cap body through the third chamber.
7 . The biological fluid collection device of claim 1 , wherein the venting plug is a porous plug.