Patent GB-1440465-A (GB)
Title: Analysis apparatus
IPC: G01N35/00
Filed: 1973-07-09
Abstract: 1440465 Automatic analysis; transferring and rotating micro container supports; photo-electric analysis CENTRE NATIONAL DE TRANSFUSION SANGUINE 9 July 1973 [13 July 1972 22 March 1973] 32615/73 Headings G1A and G1B AnaLysis apparatus for use in analysis of samplereagent reaction mixtures comprises means to dispense samples and reagent at a sample and reagent dispensing station, means to transfer supports each provided with a plurality of micro containers between the sample and reagent dispensing station and a reaction mixture observation station, the transfer means being arranged to rotate each support in a plane which is at an acute angle to the vertical about an axis perpendicular to the support when the micro containers thereof contain samples and one or more reagents. In the unit of the apparatus shown in Fig. 2 support plates 14 for microcontainers 16 are stacked in housing 45, each plate 14 being fed to the bottom of the stack from the preceding unit and raised past spring-loaded pawls 51 to the next position by operation of motor 48. The uppermost plate in the stack is displaced in the direction of arrow 7 to the next unit by engagement of ratchet wheels 43' in empty micro containers. All the plates within housing 45 are rotated by means of motor 52 to mix the contents of the micro containers. In the preceding unit 1 Fig. 1, (not shown), a probe (19) connected to pipes (35a) of a peristaltic pump (35) takes wash liquid from container 21 then sample from a tube 18; the wash liquid is discharged from a row of pivotable dispensing nozzles to waste at 41 and then a drop of sample which is allowed to form at the end of each nozzle is caused to fall into each micro container on abrupt stopping of the movement of the nozzles by engagement of their support arms with a (retractable) stop. The sample dispensing system is mounted on base 30 and this is stepped by motor 36 to allow introduction of sample into each row of micro containers in succession. Motor 31 then drives ratchet wheels 43 to step the plate in the direction of the next unit (shown), while reagent is added to each row of micro containers in turn by reagent dispensing nozzles 40. In unit 2 (shown) and unit 3, other reagents are added, then the plates move in turn to observation station 4 where either the reaction mixtures are inspected visually, or drops of the reaction mixtures are dispensed on to "alveoles" i.e. openings in a radiationopaque layer supported on a radiation-transparent base for optical measurement through the assembly. In another embodiment Figs. 10 to 15, (not shown), the plates may be stacked in units which are inclined to the horizontal and each plate takes up a horizontal position for sample and reagent  dispensing in the course of transfer from one unit to the next. The reagent dispensing device (Fig. 14) includes a rotor over which the peristaltic pump tubes pass. The dispensing nozzles are carried by a bar spring-loaded downwardly. During rotation of the pump motor, a cam device raises the bar for part of the rotation of the cam; the device then allows abrupt descent of the bar with the dispensing nozzles when reagent drops held by the nozzles fall into the containers. For optical measurements on the microdrops 77 of reaction mixtures on substrate (79), carriage 81 which is integral with 79 is laterally displaced on bars 82, 83 by co-operation of a rack 88 on bar 83 with a gear 87 driven by a motor 86, to make the microdrops move past optical means comprising a continuous spectrum lamp or arc lamp (92), lens 93. collimator 94 and prism 95 and a focusing system comprising elliptical mirror 90, filter 97, screen 99 having window 98, for nephelometric or fluorescence measurements, an opaque circular screen inside the mirror 90, and a photo-multiplier 91. The output of the photo-multiplier is connected to a recording device or data processing unit. After reading, carriage 81 is rapidly returned to its original position past horizontal tube 103 connected to a suction source and a tube 102 connected to a blower means for cleansing substrate 79. In an alternative embodiment (not shown), a lens system with a relatively wide angle focuses the image of elliptical mirror 90 on photosensor 91. The opaque screen inside the mirror may be pierced by an orifice covered with a flux compensating absorbent filter whose lens also forms the image on the same photosensor when the latter is a photographic film or on a second sensor when the latter is not a film. There is obtained a central circular image surrounded by an annular image. The optical-system may include one or more radiation filters 101.