Abstract: A one-piece, blow molded pipette for dispensing precise volumetric quantities of fluid. The pipette includes a strategically positioned overflow reservoir and is uniquely configured so as to precisely control the flow paths of air and fluid within the pipette so as to positively preclude the accidental dispensing of a volumetric quantity of fluid greater than the volume of the tubular portion of the device.

Abstract: A tube closure apparatus for sealing the open end of a plastic tube, such as the tip of a pipette, comprising a sealing element constructed of a fluoroplastic material and a heating element for controllably heating the sealing element to a temperature greater than the melting temperature of the plastic tube. Unlike a metal sealing element, the fluoroplastic sealing element resists any tendency of the molten plastic tube to stick to the sealing element. Accordingly, a uniform sealing bead can be efficiently and reproducibly formed at the open end of the plastic tube. The heating element can be heated by resistance, induction, conduction or other suitable means.

Abstract: A pipette having an integral stem and bulb and produced from a blank of plastic, stretchable molded material, said molded blank having a section of smaller cross sectional area than the remainder of the blank and the method consisting of cold stretching the section to reduce its dimensions in order to provide a reduced tip or other portion for the pipette, the stretching of said section resulting in a reduction of approximately 55% in the original dimensions of the section.

Abstract: A medical liquid bottle having a threaded neck of one thermoplastic material is blow-molded at pressures of 50 to 150 psi (3.52 to 10.1 kg/cm.sup.2) so there is a low amount of internal stress in the neck. A cap of a different thermoplastic material is injection molded at pressures of 5,000 to 20,000 psi (352 to 1,410 kg/cm.sup.2) producing a very high internal stress in this cap. After liquid has been placed in the bottle and the cap assembled to the neck, the bottle with the combined cap and neck are stress relieved by subjecting to steam sterilization at 240.degree. F. to 260.degree. F. (116.degree. C. to 127.degree. C.). This causes the cap to shrink more than the neck and to form a bacteria-tight thermoplastic-to-thermoplastic hermetic seal. Despite this very tight hermetic seal the closure is openable with an unexpectedly low unscrewing torque of 10 to 30 inch-pounds (11.5 to 34.5 centimeter-kilograms) manually applied by a nurse or physician.