Patent ID: 8528426

Claim:
A plastics cannula for use in removing samples of fluid from a container sealed with a pierceable membrane, the cannula including an elongate body having a front end and a rear end; a first bore extending from the rear of the body toward the front end; a small diameter needle like portion extending from the front end of the body having a pointed forward end shaped to allow forcible penetration through the membrane and having a second bore therein that extends from the forward end through the front end of the body to be in fluid communication with the first bore; the cross-section area of the first bore being significantly greater than that of the second bore, and an insert located within the first bore and extending from the front end of the first bore to the rear end to define a passageway from the second bore to the rear of the body, formed between an outer surface of the insert and a surface of the first bore; wherein the passageway has a significantly smaller volume than the first bore, and wherein the insert has a longitudinally extending recess that, with a part of the first bore, defines the passageway.