	US 12,436,156 B2
	Methods of determining pH and calcium or chloride concentration in samples
Yamuna Krishnan, Chicago, IL (US); Kasturi Chakraborty, Chicago, IL (US); Ka Ho Leung, Chicago, IL (US); and Anand Saminathan, Chicago, IL (US)
Assigned to THE UNIVERSITY OF CHICAGO, Chicago, IL (US)
Appl. No. 17/295,704
Filed by The University of Chicago, Chicago, IL (US)
PCT Filed Dec. 2, 2019, PCT No. PCT/US2019/064053 § 371(c)(1), (2) Date May 20, 2021, PCT Pub. No. WO2020/117701, PCT Pub. Date Jun. 11, 2020.
Claims priority of provisional application 62/774,314, filed on Dec. 2, 2018.
Prior Publication US 2022/0011325 A1, Jan. 13, 2022
Int. Cl. G01N 33/84 (2006.01); C12Q 1/6825 (2018.01); G01N 33/58 (2006.01); C07H 21/04 (2006.01)

CPC G01N 33/84 (2013.01) [C12Q 1/6825 (2013.01); G01N 33/582 (2013.01)]

18 Claims

1. A method for simultaneously determining 1) pH, and 2) Ca²⁺ concentration or Cl⁻ concentration in a sample comprising:

providing a nucleic acid complex comprising

a first single-stranded nucleic acid molecule comprising a Ca²⁺ fluorophore or a Cl⁻ fluorophore crosslinked to the first strand; and

a second single-stranded nucleic acid molecule that is partially or fully complementary to the first single-stranded molecule,

wherein the nucleic acid complex further comprises a first label conjugated to the first single-stranded nucleic acid molecule or the second single-stranded nucleic acid molecule and the first label is capable of producing a signal, wherein the intensity of the signal is dependent on change in pH;

measuring the intensity of the signal; and

determining the pH, and Ca²⁺ or Cl⁻ concentration from the measured signal by comparing to a reference value.