Method of assaying biologically active substances and labelling agents therefor
AssigneeToray Industries, Inc.
InventorsTakafumi Uchida, Shuntaro Hosaka
Life of this patent
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Abstract
A method of assaying biologically active substances by the competitive method or by the sandwich technique, characterized in that fine particles having a diameter of 0.03 to 3 .mu.m are used in the labelling agent.
Claims16
A competitive method of assaying a biologically active substance wherein amounts of a biologically active substance to be assayed are previously calibrated against amouts of a labelled biologically active substance remaining in solution by competitively reacting (i) known amounts of an unlabelled biologically active substance, (ii) a predetermined amount of the same biologically active substance labelled with a labelling agent, and (iii) a predetermined amount of a hydrophilic solid phase having fixed thereon a known number of bonding partner(s) capable of specifically bonding with the biologically active substance;
- separating the hydrophilic solid phase with the labelled and non-labelled substance bonded thereto;
- and measuring the amounts of labelled biologically active substance remaining in solution comprising the steps of:
- a. competitively reacting:
- (i) the biologically active substance to be assayed in a sample solution;
- (ii) the predetermined amount of the same biologically active substance labelled with a labelling agent, the labelling agent comprising hydrophilic fine particles having a diameter of about 0.03-3 .mu.m;
- and
- (iii) the predetermined amount of the hydrophilic solid phase;
- and
- b. measuring the amount of labelled biologically active substance remaining in the solution, said amount being quantitatively related to the concentration of said biologically active substance to be assayed.
A sandwich method of assaying a biologically active substance with the use of a labelling agent, the labelling agent including hydrophilic fine particles having a diameter of about 0.03 to 3 .mu.m, comprising the steps of:
- a. reacting in a solution:
- (i) the biologically active substance to be assayed;
- and
- (ii) an amount of a hydrophilic solidm phase, the amount of the hydrophilic solid phase being in excess of the amount needed to bond all of the biologically active substance (i), the hydrophilic solid phase being separable from the hydrophilic fine particles, the hydrophilic solid phase having fixed thereon a bonding partner capable of specifically bonding with the biologically active substance to be assayed;
- b. separating the hydrophilic solid phase, with the biologically active substance bonded thereto, from the solution;
- c. reacting the separated hydrophilic solid phase with a known excess amount of a labelled substance which has the property of specifically bonding with said biologically active substance to be assayed and which has been labelled with said labelling agent, to form a sandwich structure and thereby ensuring that a portion of the labelled substance remains unbonded to the biologically active substance;
- and
- d. measuring the amount of labelled substance remaining in the solution after step (c) in order to assay the biologically active substance.
Dependencies are inferred from the claim text.