Measuring agglutination of red blood cells for blood grouping etc. - to give numerical factor calculated from multipoint opacity determination

摘要

A sample of a mixt. of blood and a reagent is spread onto an area of specified shape and size, partic. onto an area of a transparent slide, to a thickness contg. 2 to 3 superimposed red blood cells. A ray of light is passed through the layer at several points within the defined area. For each point the loss of light through the layer is measured and a weighting value allocated to this loss which is between nil loss and complete obscurity. The weighting values for all points are taken into account in a calculation which produces a numerical 'agglutination factor' for the blood sample tested. Pref. if Pi=points of agglutination; NV=number of points of non-agglutination; and FA=agglutination factor then FA(per cent)=(Pi x 100)/NV. Used in immuno-agglutination tests, partic. to determine blood groups and rhesus factors. Also applicable to any blood test in which a reagent is used to modify the opacity of blood. System reduces the cost of mass testing of blood samples. The time for each test is very brief and the results precise and objective. Only tiny test samples are required.