Competitive immunochromatographic analysis method and immunochromatographic sensor
Inventors
MISAWA, Kazushi • Citterio, Daniel • Yamazaki, Hiroki • Yamamoto, Tomohiro
Assignees
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Publication Number
US-12188928-B2
Publication Date
2025-01-07
Expiration Date
Abstract
[Problem to be solved by the invention]The purpose of the present invention is to provide a competitive immunochromatographic analysis method and immunochromatographic sensor using said analysis method capable of intuitively displaying a molecular concentration of a substance to be measured and facilitating visual judgement of the molecular concentration.[Problem to be solved by the invention]Competitive immunochromatographic analysis method according to the present invention is characterized in that the method comprises a step for supplying a mixed solution, in which a test solution containing a substance to be measured A and a labeled antibody B are mixed, to one or more judgement parts wherein said judgement parts are formed by immobilizing a text antibody C which specifically reacts with the labeled antibody B specifically reacting with the substance to be measured A on a membrane carrier in the form of character(s) or figure(s) and immobilizing a mask antigen D composed of the same antigen as the substance to be measured A on the membrane carrier so as to surround said text antibody C,a step for competitively binding the labeled antibody B to the substance to be measured A, the mask antigen D and the text antibody C on the judgement parts,a step for judging the concentration of the substance to be measured A based on the signal from the labeled antibody B bound to the text antibody C and the mask antigen D.
Core Innovation
The invention relates to a competitive immunochromatographic analysis method and immunochromatographic sensor in which a substance to be measured A and a labeled antibody B are supplied as a mixed solution and are mixed to one or more judgement parts. Each judgement part is formed on a membrane carrier by immobilizing a text antibody C that specifically reacts with the labeled antibody B, and immobilizing a mask antigen D on the membrane carrier such that the mask antigen D surrounds the text antibody C.
In the method, the mixed solution is competitively bound to the mask antigen D and the text antibody C on the judgement parts, so that the concentration of the substance to be measured A is judged based on the signal from the labeled antibody B bound to the text antibody C and the mask antigen D. The visual judgement is semi-quantitative and uses characters or figure(s) formed by the immobilized text antibody C, with the contrast resulting from the signal related to the binding to the text antibody C versus the mask antigen D.
The invention further provides multiple judgement parts with adjustable amounts or ratios of the text antibody C and the mask antigen D to tune a judgement cutoff sensitivity. Multiple judgement parts are arranged with different C:D ratios, including judgement parts placed downstream and upstream along a flow direction in which the downstream ratio of mask antigen D to text antibody C is lower or higher than in upstream judgement parts.
The membrane carrier is fabricated by inkjet printing the text antibody C and the mask antigen D, using print cycles to tune the printed amounts.
Claims Coverage
The independent claim defines a competitive immunochromatographic analysis method that judges the concentration of substance to be measured A from labeled antibody B signals on judgement parts formed by immobilized text antibody C and surrounding mask antigen D, the same antigen as A. The dependent claims refine the independent claim with quantitative upstream/downstream C:D ratio variation across multiple judgement parts and with inkjet printing of text antibody C and mask antigen D.
Judgement part formed by text antibody C and surrounding mask antigen D
One or more judgement parts are formed on a membrane carrier by immobilizing a text antibody C in the form of character(s) or figure(s) and immobilizing a mask antigen D, which is the same antigen as the substance to be measured A, so as to surround the text antibody C.
Competitive binding judged from labeled antibody signals on text antibody C and mask antigen D
A mixed solution having the labeled antibody B and the substance to be measured A is competitively bound to the mask antigen D and the text antibody C on the judgement parts, and the concentration of the substance to be measured A is judged based on the signal from the labeled antibody B bound to the text antibody C and the mask antigen D.
Varying text antibody C and mask antigen D ratio across multiple judgement parts
Multiple judgement parts are provided on a membrane carrier in which the ratio of the amount of text antibody C to the mask antigen D differs among the judgement parts.
Directional upstream/downstream ratio control of mask antigen D relative to text antibody C
Multiple judgement parts are provided on a membrane carrier along a flow direction of a test solution such that the downstream judgement part has a lower ratio of mask antigen D to text antibody C than upstream judgement parts, or the downstream judgement parts have a higher ratio of mask antigen D to the text antibody C than the upstream judgement parts.
Inkjet printing of text antibody C and mask antigen D on the membrane carrier
Text antibody C and the mask antigen D are inkjet printed on the membrane carrier.
The core claimed approach is forming character- or figure-shaped judgement parts from immobilized text antibody C surrounded by a mask antigen D, using competitive binding of a labeled antibody B to generate a judgement signal, and judging the concentration of A based on the labeled antibody B signal associated with both C and D. Additional inventive features include varying the C:D ratio across multiple judgement parts, including upstream/downstream directional ratio control, and fabricating the judgement parts by inkjet printing.
Stated Advantages
Provides a semi-quantitative, visually intuitive concentration readout based on judgement parts.
Uses the surrounding mask antigen D to generate contrast between signals associated with the text antibody C and the mask antigen D for concentration judgement.
Tunable judgement cutoff sensitivity by adjusting ratios of mask antigen D to text antibody C across multiple judgement parts.
Directional adjustment of the judgement sensitivity by setting different upstream versus downstream ratios of mask antigen D relative to text antibody C.
Allows fabrication of the judgement parts by inkjet printing text antibody C and mask antigen D on a membrane carrier.
Documented Applications
Illustrative embodiments using human IgG and anti-human IgG labeled with gold colloid as target/substance to be measured A and labeled antibody B.
Illustrative embodiments using 8-OHdG with anti-8-OHdG, including results across multiple target concentrations by varying printed amounts of text antibody C and mask antigen D.
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