Abstract: In general, the invention is an improved device and method of obtaining body fluid samples from an indwelling catheter. A valve having ports for attachment of a catheter, attachment of a fluid line, and collection of fluids has positions that allow fluid to be removed from the catheter, fluid to be removed from the fluid line, and fluid in the fluid line to be introduced into the catheter. A connector inserted in the collection port forms a fluid-tight seal with the collection port and communicates with a needle which protrudes outwardly in a manner that allows the needle to penetrate a sealing member. Protective means associated with the needle prevents inadvertent contact by the user with the needle or with fluid adhered to the needle. The needle is constructed to removably receive a vacuum collection tube with a penetrable sealing member in a manner that penetrates the sealing member and applies the force of the vacuum of the tube to the needle and to the collection port.