United States Patent  [ii] Patent Number: 5,551,487
Gordon et al.  Date of Patent: Sep. 3, 1996
 MICRO-DISPENSER FOR PREPARING ASSAY PLATES
 Inventors: Gary B. Gordon, Saratoga; Scott A. Conradson, Palo Alto; Kay Lichtenwalter, San Jose, all of Calif.
 Assignee: Hewlett-Packard Company, Palo Alto, Calif.
 Appl. No.: 401,520
 Filed: Mar. 10,1995
 Int. CI.6 B65B 43/42; B67C 3/00
 U.S. CI 141/1; 141/130; 422/100;
 Field of Search 141/1, 231-233,
141/247, 351, 352, 356, 357, 130; 422/100;
 References Cited
U.S. PATENT DOCUMENTS
2,874,734 2/1959 Luckock et al 141/356
4,041,995 8/1977 Columbus 422/100
4,632,808 12/1986 Yamamoto et al 422/100
4,699,884 10/1987 Noss et al 422/100
5,046,539 9/1991 MacLeish et al 422/100
5,443,791 8/1995 Cathcart et al 436/180
Primary Examiner—Henry J. Recla
Assistant Examiner—Steven O. Douglas
A method and apparatus for dispensing immobilized reactants onto substrates for use in generating a biological assay plate for detecting the presence of mobile reactants that bind to the immobilized reactants. The apparatus includes a dispensing bed that holds a plurality of substrates. Each potential immobilized reactant is held in a cartridge. The apparatus includes a holder that allows any of these cartridges to be used in dispensing an immobilized reactant. The apparatus includes a positioning mechanism for positioning the cartridges over each of the substrates. The positioning mechanism also allows a cartridge so positioned to be brought into contact with each of the substrates at a predetermined location on each of the substrates so as to dispense a known quantity of the immobilized reactant onto the substrate at that location. In the preferred embodiment of the present invention, the cartridges include a chamber for holding the immobilized reactant and a channel having a first end communicating with the chamber. The second end of the channel provides the exit path through which the immobilized reactant exits when the cartridge is brought into contact with the substrates.
4 Claims, 3 Drawing Sheets