Reaction cuvette

#1. Field of the Invention

#This invention relates to a novel reaction cuvette structure and, more particularly, to a novel reaction tray comprised of a plurality of reaction cuvettes for use in automated analysis systems.

#2. Description of the Prior Art

#FIG. 1A is an isometric view of the reaction tray, which is comprised of a plurality of novel reaction cuvettes; FIGS. 1B is an isometric view of one such reaction cuvette;

#FIGS. 2A and 2B are illustrative of the aspirating cycle and FIGS. 3A, 3B and 3C are illustrative of the dispensing cycle of an aspirating/dispensing probe, such as described in U.S. Pat. No. 4,121,466, supra;

#FIGS. 4A and 4B provide a cross-section view of the reaction cuvette of the present invention; and

#Referring to FIG. 1, the reaction tray 1 of the present invention comprises a plurality of cup-like containers or cuvettes 3, formed in integral fashion and arranged circularly along the periphery of tray 1. Tray 1 is preferably molded of clear acrylic polystyrene or other suitable transparent inert material. Reinforcing ribs 4 provide rigidity to tray 1. Tray 1 is adapted to be mounted through a central opening 5 and keyed by slot 7 to an intermittently rotated shaft, not shown, to rotate about its axis, as indicated by the arrow. A collar 9 is provided which defines slot 7 and facilitates positioning and removal of tray 1 from such shaft. Rotation of such shaft is operative to position each cuvette 3 successively at a reagent dispensing station 11, a sample dispensing station 13, and at an optical readout station 15. As the use of reaction trays in discrete-type analytical systems is well understood and in the interest of expediency, such stations have not been illustrated in detail. Rather, dispensing probes 17 and 19 are shown as symbolic of the reagent and sample dispensing stations, respectively. Probes 17 and 19 are each adapted, as indicated by the arrow, to be displaced vertically, so as to be introduced into and withdrawn from the cuvettes positioned at the reagent and sample dispensing stations 11 and 13, respectively. It will be appreciated that probes 17 and 19, when elevated, are adapted to be rotated in a horizontal plane, so as to be positioned at aspirating stations located over sources of reagent and sample, respectively. When so positioned, the probe 17 would be immersed into such reagent source selectively to aspirate a predetermined volume of reagent which is dispensed into a cuvette 3 located at the dispensing station 11. Also, when such cuvette 3 has been advanced to the sample dispensing station 13, the probe 19 would be immersed into such sample source to aspirate a predetermined volume of sample which is dispensed and reacted in such cuvette. The aspirating and dispensing cycles of probes 17 and 19 are more particularly described hereafter and may take the general form of the aspirator-dispenser unit described in U.S. Pat. No. 4,121,466, supra. Subsequently, the cuvette 3 is advanced to optical readout station 15, whereat the analyte is colorimetrically analyzed, by conventional techniques.

#As illustrated in FIGS. 1A and 1B, each cuvette 3 has a substantially rectangular configuration and extends downwardly from the plane of reaction tray 1. Each cuvette 3 includes opposing parallel walls 21 and 21' and 23 and 23', the latter defining tapered portions 25 and 25', respectively. Wall portions 25 and 25' are integral with tab portions 27 and 27', respectively. In the showing of FIG. 1A, tab portions 27 and 27' are integrally defined in tray 1. However, tab portions 27 and 27' would allow support, if cuvette 3 is to be mounted in slots defined in a non-disposable type of turntable. The bottom surface of each cuvette defines a plurality of upwardly extending projections or ribs 31, whose particular function is hereinafter described. Opposing walls 21 and 21' of each cuvette 3 are at a precisely controlled separation. Walls 23 and 23' define a sight path to colorimetrically analyze the reacted sample. When a cuvette 3 is positioned, in turn, at readout station 15, a light beam from source 33 is directed through lense arrangement 35 and along such sight path. The emerging light is incident on detector 37, which produces an output indicative of the concentration of the analyte being measured and which is recorded by recorder 39.

#To appreciate the advantages of the present invention, reference is initially made to FIGS. 2A and 2B, which illustrate the aspiration cycles of both probes 17 and 19 of FIG. 1. A container 41 is representative of the reagent source and of sample source into which probes 17 and 19, respectively, of FIG. 1A would be immersed. Also, probe 43 is representative of probes 17 and 19. It will be appreciated that the respective operations of probes 17 and 19 are identical, except in respect of the particular aqueous liquid to be aspirated, i.e., sample or reagent. Conventionally, probe 43 is immersed into container 41 and a controlled negative pressure is applied at the outlet end, as by a pump, to aspirate a controlled volume of the aqueous liquid 45. As particularly described in U.S. Pat. No. 4,212,466, supra, an immiscible fluid 47 is flowed downwardly, at a controlled rate, over outer surface of probe 43 from a chamber, not illustrated, to coat such surface and prevent contact with the liquid to be aspirated. During immersion of probe 43, to effect either an aspirate or dispense operation, the flow of immiscible liquid may be discontinued.