The invention concerns a novel sample tube and a method of manufacturing a such a sample tube. According to the method an oversized mold cavity is formed with an opposing pair of mold members of an injection molding machine, the mold members being movable relative to each other and between which mold members the sample tube is formed. A volume of resin exceeding the prescribed volume of the sample tube is injected into the cavity and force is applied to said mold members in order to reduce the volume of said mold cavity for displacing molten polymer in the cavity and for compressing the polymer to form said sample tube. By means of the invention, sample tubes and vessels having ultra thin walls can be manufactured.