User controlled off-center light absorbance reading adjuster in a liquid handling and reaction system

• US 4,873,633 A
• Filed: 09/11/1986
• Issued: 10/10/1989
• Est. Priority Date: 10/18/1985
• Status: Expired due to Term

• Current Assignee: Cetus Corporation (Bayer AG)
• Original Assignee: Cetus Corporation (Bayer AG)
• Inventors: Noorda, Brent S., Moehle, Stephen J., Zeitlin, James A., Albom, Bradley S., Coppock, Stan, Widunas, Joseph T., Mezei, Louis M.
• Primary Examiner(s): Jablon, Clark A.
• Application Number:
  US06/906,101
• Time in Patent Office: 1,125 Days
• Field of Search: 364/416, 364/555, 422/73, 356/39, 356/442, 356/440
• US Class Current: 356/39
• CPC Class Codes: G01N 33/80 involving blood groups or blood types or red blood cells white blood cells G01N33/56972
• CPC Class Codes: G01N 35/00 Automatic analysis not limited to methods or materials provided for in any single one of groups G01N1/00 - G01N33/00; Handling materials therefor

Abstract

A host computer controls a plate reader which optically reads the results between donor samples and reagents. The system provides the user with the ability to change the position of off-center light absorbance readings to maximize the power of the machine to discriminate between positive and negative agglutination reactions. In addition, the user can tailor thresholds for absorbances used to distinguish between positive, negative and "no type determined" reactions.

Claims

1. An apparatus for optimizing the accuracy of light absorbance readings taken by a plate reader regardless of the type of plate and type of well in said plate comprising:

means for causing the plate reader to take multiple light absorbance readings at different locations across the bottom of each well;

means for displaying the absorbance readings in graphical form to a user and for displaying the current locations of at least one off center absorbance reading used to discriminate positive reactions from negative reactions;

means for allowing the user to move the locations of the off center absorbance reading relative to the rest of the graphic display to optimize the discriminatory powers of the system to distinguish between positive and negative reactions; and

means to record the user'"'"'s choice for the position of the off center reading for use in further plate reading operations.

2. The apparatus of claim 1 wherein the means for graphically displaying the absorbance data and for allowing the user to move the position of the off center reading is a host computer and further comprising:

means for allowing the user to perform automated liquid handling on each different plate type using a sequence of liquid handling steps which is customized for that plate type;

means for reading a bar code on each plate type and for sending this data to said host system with tag data for plates which have predetermined liquid handling sequences, said tag data indicating that the plate has a well bottom geometry for which the plate reader system is not currently optimized;

means in said plate reader for reading the bar codes on plates placed therein for reading and for sending the bar code data to said host system;

means in said host system for looking up the bar code data received from the plate reader and determining whether the plate is a type for which the plate reader has not been optimized in position of the off center reading;

means for controlling the plate reader to cause said means for causing multiple absorbance readings to be taken to take said readings.

3. An apparatus in an automated blood assay system including a plate reader to allow a user to control the position at which the plate reader takes its off well bottom center light absorbance readings comprising:

means to measure light absorbance along a plurality of paths through the well bottom;

means to graphically display each absorbance versus the position relative to the well bottom center of the path to which each absorbance corresponds and to display the current path being used for the off center light absorbance reading used in the blood assay; and

means for allowing the user to redefine the desired path for the off center light absorbance reading by graphically moving a pointer to the desired path position.

4. An apparatus for performing automated blood grouping on donor samples comprising:

a computer directed liquid handler means to perform predetermined automated sequences of operations involving placing aliquots of donor red blood cells and plasma into a plurality of wells in a plurality of assay trays and placing predetermined reagents in predetermined ones of said assay wells;

a computer directed plate reader to measure light absorbance data for the wells in said trays; and

a host computer for sending commands to control the operations of said plate reader and said liquid handler and for collecting, analyzing and storing the light absorbance data from said plate reader to determine the blood group and type of each donor'"'"'s blood, said host computer also having means therein for allowing the user to define graphically the optimum position for shining light through the bottom of one of said assay wells to measure light absorbance so as to maximize the accuracy of the host computer in determining blood group and type including means to cause said plate reader to measure the light absorbance along a plurality of different paths through the bottom of a well containing a positive reaction agglutination button and to send said data to said host computer and including means to display the light absorbance along said plurality of different light paths through said well as a graph of light absorbance versus steps off center of well bottom center for each said path and including means for graphically displaying the current position for at least one off well bottom center light absorbance reading used for measuring light absorbance in automated blood assay and for allowing the user to graphically alter the position at which this off well bottom center light absorbance reading is taken by moving the marker on the light absorbance graph.

5. The apparatus of claim 4 further comprising:

means in said liquid handler to read the bar codes of test tubes containing donor samples and the bar codes of trays into which the donor samples are deposited and for sending this data to the host computer for storage in a look up table and further comprising means for appending either a steps off center code or a histogram code to bar codes for trays whose light absorbance data is to be graphically displayed to the user;

means in said plate reader for detecting these histogram or steps off center codes and for sending same to said host computer along with light absorbance data from each well in each tray along with data labelling the light absorbance data for each well from each tray with identifying information locating the well and tray from which the data came; and

means in said host computer for storing and analyzing the data from the plate reader to determine the blood group and type of each user including means for processing the data from each well in which the same type reagent was placed into histogram format and for graphically displaying same to the user along with the absorbance values currently set as the positive and negative reaction discrimination thresholds and for allowing the user to graphically adjust the positions and absorbance values for said thresholds.

6. The apparatus of claim 5 further comprising means in said host computer for allowing the user to put a known blood group and type into the liquid handler and for displaying the known reaction template for that known blood group and type on a display and for using the new thresholds to experimentally determine a reaction template for reactions to all the conventional reagents used in blood typing and for displaying the experimentally determined reaction template on the same display with the known template for that blood group and type for comparison by the user.

7. The apparatus of claim 6 further comprising means in said host computer for allowing the user to change the thresholds on the histograms until the number of no type determined donor samples or the matching between the known templates and the experimentally determined templates using the new thresholds is acceptable.