The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 12, 1999
Filed:
Nov. 12, 1997
Amer El-Hage, Menlo Park, CA (US);
Joseph Leytes, Moutain View, CA (US);
LJL BioSystems, Inc., Sunnyvale, CA (US);
Abstract
A piston is disposed inside a tube having an inner cross sectional size and shape uniform along its length. The tube has an open end. The piston is free to move linearly inside the tube and preferably may move out of the tube through the open end. If the tube is cylindrical, for example, it has a constant inner diameter. The open end of the tube is neither tapered or flaring. Liquid samples are aspirated into the device by pulling the piston back. The sample is then ejected by accelerating the piston to a minimum velocity to force the liquid sample out of the open end of the tube. The velocity of the sample is sufficient to render negligible the effects of surface tension forces. The volume of the liquid sample dispensed is determined by the inner diameter of the tube and the piston displacement. Accurate positioning of the piston provides samples of accurate volumes. A specific embodiment of the present invention uses a tube with an inner diameter of 0.5 mm, resulting in a volume displacement of 1.9 microliters per centimeter of piston travel.