METHOD AND APPARATUS FOR THE MEASUREMENT OF THE PROPERTIES OF AN AGGLUTINATION

Abstract: Method and apparatus for the measurement of the properties of an agglutination, a precipitate (4), or of a corresponding reaction result placed on the bottom (3) of a vessel (1) by means of radiation and of a detector (6)that receives radiation. The beam of measurement (5) coming from the source of radiation passes substantially in the direction of the vertical axis of the vessel, and the intensity of the radiation passing through, or reflected from, the precipitate on the bottom of the vessel is measured. According to the invention, in order to measure the formation, location, and form of the agglutination or precipitate and/or the density or other properties of different points of the agglutination or precipitate, a component field out of the field of the vessel (1) bottom (3) to be measured is measured, the source of radiation is moved in relation to the detector (6) and the vessel (1) so that the component field at each particular time subject to measurement moves along the entire field of vessel (1) to be measured. For the purpose of processing of the information and production of the output, the location of the component field at each particular time under measurement and the intensity of the radiation at the said point are determined at specified intervals by means of a detector (6) that indicates the position at which the beam of measurement arrives on the face of the detector.

Description: Method and, apparatus for the measurement of the prop_gχϋ_es_, of an agglutination- The present invention is concerned with a method for the measurement of the properties of an agglutination, a precipitate, or of a corresponding reaction result placed on the bottom of a vessel by means of radiation and of a detector that receives radiation, whereat the beam of measurement coming from the source of radiation passes substantially in the direction of the vertical axis of the vessel, and the intensity of the radiation passing through, or reflected from, the precipitate on the bottom of the vessel is measured. The invention is also con¬ cerned with an apparatus for the implementation of the method, to which apparatus one or several measurement vessels can be fitted and which apparatus comprises one or several sources of radiation, one or several detectors receiving radiation, the said detector(s) being placed so that the beam of measurement received by the detector passes substantially in the direction of the vertical axis of the vessel to be fitted to the apparatus, as well as an output unit. Various tests based on agglutinations are in common use, e.g., in the case of blood-group identifi¬ cations, antibody determinations, and rheumatic-factor measurements. In blood-group analytics and in antibody determinations the agglutination of red blood cells is concerned, whereas, e.g., the rheumatic factor is commonly measured by means of the agglutination of latex particles. It has been customary to read the results of agglutination reactions visually. An experienced reader is also quite skilful in distinguishing between aggluti¬ nation and non-agglutination. Such a mode of output is, however, quite subjective, and this is why the result is not always completely reliable. In clear situations with strong agglutination, visual reading is certainly no problem, but weak reactions of agglutination are often problematic. OMPI &RUll Among agglutination reactions, most difficult to interpret is, e.g., a weak Rh-positive result obtained in blood-group identifications. In such situ¬ ations it is of essential importance to obtain a reliable output, because the safety of the patient is concerned. The objective of the method in accordance with the invention (observation of, e.g., agglutination reactions and reading of the final results) is to be able to ascertain the difference between agglutination and non-agglutination sufficiently clearly and reproducibl . By means of the principle of vertical measurement (Suovaniemi, Osmo, "Performance and Properties of the Finnpipette Analyzer System", Proceedings of the Second National Meeting on Biophysics and Biotechnology in Fin- land, 183, 1976) it is possible to measure agglutination reactions. However, in the case of very weak aggluti¬ nations, one beam of light does not produce a sufficient difference in absorbance between agglutination and non- agglutination. In the method in accordance with the in- vention the measurement is improved by registration of the agglutination result from several points. In prior art such a position-sensitive detector is known by whose means it is possible to indicate the location of a point of light produced by the source of light on the detector face by means of x- and y-coordi- nates and, at the same time, to measure the intensity of the radiation arriving at the detector at each particular " point. The beam of light may move completely arbitrarily on the detector face. The method in accordance with the invention is characterized in that, i order to measure the formation, location, and form of the agglutination or precipitate and/or the density or other properties of different points of the agglutination or precipitate, a component field out of the field of the vessel bottom to be measured is measured, the source of radiation is moved in relation to the detector and the vessel so that the component field ^ '* ϋREA "?f ( OMPI WIPO at each particular time subject to measurement moves along the entire field of vessel 1 to be measured, and, for the purpose of processing of the information and production of the output, the location of the component field at each particular time under measurement and the intensity of the radiation at the said point are deter¬ mined at specified intervals by means of a detector that indicates the position at which the beam of measurement arrives on the face of the detector. The apparatus in accordance with the invention is characterized in that the source of radiation, which covers only a component field out of the bottom of the vessel at a time, can be shifted in relation to the vessel and to the detector so that the component field to be measured out of the bottom of the vessel, on the bottom of the vessel, can be exchanged, and that the detector is a detector in itself known which indicates the location of the beam of measurement and the intensity of the radiation at the said location. It is characteristic of the method and appara¬ tus in accordance with the present invention, besides the vertical measurement (like in FP-9 and FP-90 photo¬ meters, of Labsystems 0Y 3 or Titertek Multiscan readers, Eflab Oy, U.S. Patent 4,144,030) that 1. One or several vessels of measurement are in position above or underneath the beam of measurement during measurement. 2. The beam of measurement may consist, e.g., of a beam of light, of radiation of a certain wavelength, of a laser beam, etc., and the beam of measurement at each particular time used passes along the desired route at the vessel of measurement (cuvette) or vessels of measurement placed in a matrix (set of cuvettes). 3. The beam of measurement at each particular time used may be either focused or unfocused onto the appropriate point of the detectors or of the precipitate to be measured. BAD 4. The formation and/or the final state of the precipitate or corresponding reaction result on the bottom of each vessel of measurement can be followed and/or measured point by point at the points and along 5 the routes that are most appropriate in each particular case. 5. Above or underneath the vessel or vessels of measurement there is a detector, which is, e.g., dual-axis position-sensitive and which thereby gives 10 constant information on position on the x- and y-axes concerning the movements of the beam of measurement on the detector face. It follows from this that, when the beam of measurement moves at each reaction vessel along the desired route, information is received by means of 15 the detector concerning the position of the beam of measurement and the corresponding intensity of the beam of measurement. The invention will be described below in more detail with reference to the attached drawings, wherein 20 Figure 1 shows a vessel of measurement and a detector, and Figure 2 shows a cuvette-set matrix and a detector. In Figure 1 a vessel of measurement 1 is shown 25 that contains a reaction mixture 2 and a reaction result 4 on the bottom 3 of the measurement vessel, e.g. a result of an agglutination reaction. A beam of measurement 5 arrives in the vessel of measurement 1, whose source moves within the x-y system of coordinates. The beam 30 of measurement 5 passes through the reaction result 4 to the detector 6, which registers the intensity and the location of the beam of measurement in relation to the reaction result 4 and/or, if necessary, also in relation to the vessel of measurement 1. When the beam 35 of measurement 5 moves within the x-y system of coordi¬ nates, the reaction result 4 can be registered point by point, and the information obtained in this way is used for the determination of the final result. Figure 2 shows a cuvette-set matrix 7 which includes several vessels of measurement (cuvettes) 1, on whose bottoms a reaction result 4 has been formed or is about to be formed. Each cuvette is measured by means of the beam of measurement 5 moving within the x-y system of coordinates, and pair values of intensity and position of the beam of measurement are obtained from each cuvette 1 to the detector corresponding each particular cuvette or to a wide detector 6 in accordance with the desired program. It is evident that each cuvette in the cuvette- set matrix 7 may also have a detector of its own which is capable of registering both the intensity of the beam of measurement and the position of same in relation to the reaction result 4 placed in the cuvette 1. The invention is not confined to the above embodiments only, but it may show even considerable variation within the scope of the patent claims. The method of measurement may, of course, being a single-channel or multi-channel method (one or several vessels of measurement), be additionally based, e.g., on turbidometry, fluorometry, or, e.g., on the use of a source of radiation and a receiver for luminescence, laser beam, ultrasound, etc. phenomena, either one of them at a time or as a desired combination. The positioning of the measurement vessels, of sources of measurement beams, of detectors, etc. auxiliary equipment may be performed in the way most appropriate in each particular case. The equipment may also involve various degrees of automation, e.g., in the pipetting of the samples and reagents, in the shifting of the beams of measurement, and in the processing of the results. It is evident that, in stead of one method of measurement, the measurement vessels (cuvettes) may be measured subsequently by means of two or more wave lengths (Suovaniemi, Os o: multichromatic measurement) or methods of measurement (e.g., photometry and fluorometry), the final result being based on the information thereby ob ained. In addition to one registration, it is possible to register the vessel of measurement or each vessel of measurement several times subsequently, at specified intervals of time, whereby it is possible to observe the formation of the reaction result, e.g., out of agglu¬ tination or corresponding reaction result on the bottom of the vessel of measurement. A certain type of pattern in the process of formation of the reaction result is also characteristic of some reactions. The reaction result formed on the bottom of the vessel of measurement may also be observed so that the beam of measurement follows the limit of a pre- determined level or levels of intensity of the beam of measurement on the detector, whereby the reaction result yields a topography in accordance with the intensity of the beam of measurement coming onto the detector, on the detector, because by means of the detector it is pos- sible to ascertain the position corresponding each in¬ tensity within the x-y system of coordinates. _OMPI WIPO ^

Claims: WHAT IS CLAIMED IS: 1. A method for the measurement of the pro¬ perties of an agglutination, a precipitate (4), or of a corresponding reaction result placed on the bottom (3) of a vessel (1) by means of radiation and of a detector (6) that receives radiation, whereat the beam of measure¬ ment (5) coming from the source of radiation passes substantially in the direction of the vertical axis of the vessel, and the intensity of the radiation passing through, or reflected from, the precipitate on the bottom of the vessel is measured, c h a r a c t e r i z e d in that, in order to measure the formation, location, and form of the agglutination or precipitate and/or the den¬ sity or other properties of different points of the agglutination or precipitate, a component field out of the field of the vessel (1) bottom (3) to be measured is measured, the source of radiation is moved in relation to the detector (6) and the vessel (1) so that the component field at each particular time subject to measurement moves along the entire field of vessel (1) to be measured, and, for the purpose of processing of the information and pro¬ duction of the output, the location of the component field at each particular time under measurement and the inten¬ sity of the radiation at the said point are determined at specified intervals by means of a detector (6) that indicates the position at -which the beam of measurement arrives on the face of the detector. 2. An apparatus for the implementation of the method as claimed in claim 1, to which apparatus one or several measurement vessels can be fitted and which apparatus comprises one or several sources of radiation, one or several detectors (6) receiving radiation, the said detector(s) being placed so that the beam of measu¬ rement (5) received by the detector passes substantially in the direction of the vertical axis of the vessel (1) to be fitted to the apparatus, as well as an output unit, c h a r a c t e r i z e d in that the source of radiation, which covers only a component field out of the bottom (3) of the vessel (1) at a time, can be shifted in relation to the vessel (1) and to the detector so that the com¬ ponent field to be measured out of the bottom (3) of the vessel, on the bottom of the vessel, can be exchanged, and that the detector (6) is a detector in itself known which indicates the location of the beam of measurement (5) and the intensity of the radiation at the said location. 3- An apparatus as claimed in claim 2, to which a cuvette set (7) consisting of several cuvettes (1) can be fitted, c h a r a c t e r i z e d in that above or underneath each cuvette (1) there is a separate detector indicating the location of the beam of measure- ment (5)- 4. An apparatus as claimed in claim 2, to which a cuvette set (7) consisting of several cuvettes (1) can be fitted, c h a r a c t e r i z e d in that above or underneath several cuvettes (1) there is a common detector indicating the location of the beam of measurement (5). B

Inventors: EKHOLM P, KAUKANEN E, SUOVANIEMI O
Applicants: LABSYSTEMS OY
Application year: 1981
Main classification: G01N21
IPC codes: G01N21