Quantum-Si has filed a patent for luminescently labeled nucleic acid nanostructures that can detect and sequence target molecules from a sample. The nanostructure consists of at least three structural strands, a nucleotide complementary strand, and a dye-binding strand with luminescent labels. GlobalData’s report on Quantum-Si gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Quantum-Si, optoelectronic biosensors was a key innovation area identified from patents. Quantum-Si's grant share as of September 2023 was 18%. Grant share is based on the ratio of number of grants to total number of patents.
Luminescent nucleic acid nanostructures for detection/sequencing of molecules
A recently filed patent (Publication Number: US20230272470A1) describes a luminescently labeled nucleotide-bound nucleic acid nanostructure. The nanostructure consists of at least three structural strands, at least one nucleotide complementary strand, and at least one dye-binding strand. The nucleotide complementary strand is ligated to the structural strand, and the dye-binding strand contains luminescent labels.
The patent claims different variations of the nanostructure, including those with three or four structural strands. In the case of three structural strands, they are hybridized in a circular manner, with each end of one strand connected to the end of another. For four structural strands, the hybridization pattern is similar, forming a circular structure.
The nucleotide complementary strand is separated from the structural strand by a dithymine spacer sequence. The nucleotide complementary strand can contain guanine, thymine, cytosine, or adenosine nucleotides. The structural strands have a middle sequence and a clip sequence, with each clip sequence being complementary to another clip sequence. The hybridization of the structural strands is facilitated by the clip sequences.
The nanostructure can have varying numbers of nucleotide complementary strands and dye-binding strands, ranging from one to four. The clip sequence is typically 10-20 nucleotides in length. The dye-binding strands can contain one, two, or three luminescent labels.
The nanostructure is made up of nucleic acid strands, which can be single-stranded. The luminescent labels are conjugated to the dye-binding strands either after synthesis or during synthesis. The luminescent labels can be fluorescent.
The patent also describes methods of determining the sequence of a template nucleic acid using the luminescently labeled nanostructure. The methods involve exposing the template nucleic acid to the nanostructure and different types of luminescently labeled nucleotides. A series of excitation pulses is directed towards the target volume, and the emitted photons from the labeled nucleotides are detected. The sequence of incorporated nucleotides is identified by analyzing the luminescent intensity and lifetime of the emitted photons.
Another method involves immobilizing the template nucleic acid in a chip with multiple wells. The template nucleic acid is exposed to the nanostructure and labeled nucleotides, and the emitted photons are detected to determine the sequence of incorporated nucleotides. The methods can be automated or manual, and the automated method can be performed in a single instrument.