A needle structure having proximal and distal ends and including a collection needle section at a more proximal end of the needle structure and a skin plug retainer section at the very distal end and integral with the collection needle section. The collection needle section includes a generally hollow tubular member having an external surface, an inner lumen and a port through the tubular member so as to enable fluid flow from about the tubular member to the inner lumen for collection therefrom. The skin plug retainer section includes a hollow tubular piece having an external surface and an inner lumen. The hollow tubular piece is beveled at its distal end to form a needle tip. A barrier wall may be disposed intermediate the collection needle section and the skin plug retainer section.