Method for detecting particulate substance by immunochromatography, and kit for the same

A method for producing a kit for detecting a particulate substance contained in various body fluids, including breast milk, saliva, and tears, as well as blood and urine;

• preservative solutions for tissue sections;
• or cell culture supernatants by immunochromatography, the particulate substance comprising, on its surface, a plurality of substances to be bound including a first substance to be bound and a second substance to be bound that may be the same or different from each other, the method comprising steps of:
• providing a test strip comprising a membrane on which a first specific binding substance for the first substance to be bound is immobilized;
• providing, in order to block the membrane, a blocking composition comprising a polymer-based blocking agent having, in its side chain, a substituent represented by the following formula:
• (wherein R1, R2, and R2 are each independently a hydrogen atom, a C1-6 alkyl group, or a C1-6 hydroxyalkyl group;
• and n is an integer of 1 to 4), and having a weight average molecular weight (Mw) of 1×103 to 1×107;
• blocking the membrane with the blocking composition.

A kit for detecting a particulate substance contained in various body fluids, including breast milk, saliva, and tears, as well as blood and urine;

• preservative solutions for tissue sections;
• or cell culture supernatants by immunochromatography, the particulate substance comprising, on its surface, a plurality of substances to be bound including a first substance to be bound and a second substance to be bound that may be the same or different from each other, the kit comprising:
• a test strip comprising a membrane on which a first specific binding substance for the first substance to be bound is immobilized, wherein the membrane is blocked with a blocking composition comprising a polymer-based blocking agent having, in its side chain, a substituent represented by the following formula:
• (wherein R1, R2, and R2 are each independently a hydrogen atom, a C1-6 alkyl group, or a C1-6 hydroxyalkyl group;
• and n is an integer of 1 to 4), and having a weight average molecular weight (Mw) of 1×103 to 1×107;
• a second specific binding substance for the second substance to be bound, the second specific binding substance binding to a labeling substance.