Granted Patent B2

US 12,235,217 · App. 17/098,236 · Granted Feb 25, 2025

Inventors: Yunyuan Vivian Wang (Tustin, CA); Aaron Alexander Rowe (Toluca Lake, CA); Hui-Ling Koh (Santa Ana, CA); Stephen L. Chen (Tustin, CA); K C Chen (Anaheim, CA)

Assignee: Scanwell Health, Inc.

G01N21/78G01N1/34

Abstract

Claims (20)

1. A kit for quantification of porphobilinogen (PBG) in a urine sample, the kit comprising:

a) diagnostic test strip comprising:

a substrate impregnated with a dried solution comprising an acid, a reagent reactive with PBG, and one or more stabilizers;

b) a pre-processing reagent comprising urease,

wherein the amount of pre-processing reagent is sufficient to remove urea such that a 2 ml urine sample contacted with pre-processing reagent for a period of 10 seconds to 15 minutes will contain an amount of urea that is undetectable by the test strip; and

c) a cation-exchange resin device comprising a vessel and a cation-exchange resin arranged in the vessel,

wherein the cation-exchange resin binds to urobilinogen at an affinity greater than it binds to PBG, such that a urine sample of 2 ml contacted with the cation-exchange resin in the vessel for a period 5 to 20 minutes will contain an amount of urobilinogen that is undetectable by the test strip but will contain an amount of PBG detectable by the test strip.

2. The kit of claim 1 , wherein the reagent reactive with porphobilinogen comprises a benzaldehyde derivative.

3. The kit of claim 2 , wherein the reagent reactive with porphobilinogen comprises one or more selected from the group consisting of para-Dimethylaminobenzaldehyde, para-Diethylaminobenzaldehyde, 4-(N,N-bis-(2-cyanoethyl)-amino)-benzaldehyde, 4-(N,N-bis-(2-cyanoethyl)-amino)-benzaldehyde, 4-(4-Methylpiperazinyl)benzaldehyde 4-[(2-Cyanoethyl)methylamino]benzaldehyde N-Methyl-N-(2-hydroxyethyl)-4-aminobenzaldehyde, 4-[Bis[2-(acetyloxy)ethyl]amino]benzaldehyde, and 4-(Boc-amino)benzaldehyde.

4. The kit test strip of claim 1 , wherein the reagent reactive with porphobilinogen comprises an Azo dye.

5. The kit tip of claim 1 , wherein the acid comprises one or more selected from the group consisting of: oxalic acid, maleic acid, and a salicylic-derivative acid.

6. The kit of claim 1 , wherein the one or more stabilizers comprises one or more selected from the group consisting of EDTA, caffeine, borate salt, sodium benzoate, and sodium acetate.

7. The kit of claim 1 , wherein the dried solution further comprises one or more additives configured to increase bonding of the reagent to the substrate.

8. The kit of claim 7 , wherein the one or more additives comprises one or more selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, copolymers of polyvinyl pyrrolidone and polyvinyl acetate, polyglycols, methyl vinyl ether, and maleic anhydride.

9. The kit of claim 1 , wherein the substrate comprises a fiber paper.

10. The kit of claim 1 , wherein the substrate is laminated onto a backing.

11. The kit of claim 10 , wherein the backing comprises a flexible polymer.

12. The kit of claim 1 , wherein the urease is dry powder urease.

13. The kit of claim 1 , wherein the cation-exchange resin comprises one or more resins selected from the group consisting of: 1,4-bis(ethenyl)benzene; (4-ethenylphenyl)-trimethylazanium; styrene; chloride, 3-[(3-chlorophenyl)sulfonylamino]benzoic acid, and 1,2-bis(ethenyl)benzene; 1-ethenyl-2-ethylbenzene; styrene.

14. The kit of claim 1 , wherein the cation-exchange resin device is configured to couple to a fluid actuating device.

Assignments (1)

Continuity (2)

References Cited (235)

Cited By (3)

US 1,128,930 US 1,128,931 US 1,147,433