GB729765A - Means for blood grouping - Google Patents

Abstract

Means for blood grouping consists of a sheet of material having on its surface a series of separate areas each of which carries a layer of test serum produced by drying a liquid containing up to 20 per cent. by volume of serum, the serum having been diluted with conglutinin or conglutinin substitute, other than serum or plasma; the sheet should keep flat when moistened and the surface should be smooth, chemically inert, wettable but not absorbent, and capable of being moistened evenly by serum and water. The sheet may be made of strong paper, cardboard, steel, celluloid, thermoplastic or thermosetting plastics, or laminated material; the surface layer may consist of "Cellophane" (Registered Trade Mark), glued paper, gelatine, cellulose acetate, polyvinyl chloride, polymethyl acrylates, or gold; the surface layer should be attached by a water-resistant adhesive, or an intermediate layer of lacquer or metal foil should be provided. Suitable conglutinin substitutes are solutions of partially hydrolized dextran, albumin, polyvinylpyrrolidene, gum arabic, gum acacia, or high molecular weight alcohols or sugars. In making the solutions used for forming the dried layers, the test sera may be diluted with indifferent or weak sera so as to equalize the positive reactions, and then mixed in the same proportions with the conglutinin or conglutinin substitute. The solutions may also contain sodium chloride in 1-3 per cent. concentration, and coagulation-inhibiting substances such as sodium citrate, sodium oxalate, and heparine. Separate areas of the sheet carry anti-A serum, anti-B serum, anti-Rh serum, and an indifferent serum for comparison. In carrying out the test, water is added to each area of the sheet, followed by a drop of blood from the person tested; after mixing, the reactions are noted and the result recorded on the sheet.