Quantum-Si
| Quantum-Si Incorporated | |
|---|---|
| Type | Public (Nasdaq: QSI) |
| Industry | Proteomics instruments |
| Founded | 2013 |
| Founders | Jonathan Rothberg |
| Headquarters | Branford, Connecticut, United States |
| Products | Platinum, Platinum Pro, sequencing and library preparation kits |
Quantum-Si is a company in Branford, Connecticut, that sells a benchtop instrument for reading the amino acid sequences of peptides one molecule at a time. The readout is light. Each peptide is held in a well on a semiconductor chip, dye-labeled molecules called recognizers bind to the amino acid at its end, and an enzyme then clips that amino acid off so the next one can be read. No pore is involved, and the company's competitors in nanopore protein sequencing use ionic current instead.
The Platinum went on sale in December 2022 and was described in the company's release as "the world's first next-generation single-molecule protein sequencing platform".[1] In January 2025 it was joined by the Platinum Pro, which the company sells for research use only.[2][3]
History
Quantum-Si was founded in 2013 by Jonathan Rothberg, who had already founded two companies in DNA sequencing. His Yale profile credits 454 Life Sciences, which he chaired from 1999 to 2006, with the first new way to sequence genomes since the methods of Sanger and Gilbert. At Ion Torrent, which he led from 2007 to 2010, the sequencing took place on a semiconductor chip that detected the hydrogen ion released each time a nucleotide was added.[4]
The company became public in 2021. It merged with HighCape Capital Acquisition Corp., a blank-check company, in a business combination that closed on June 10, 2021, and the combined company took the name Quantum-Si and the Nasdaq symbol QSI.[5] Its scientists published the method in Science on October 13, 2022, and the Platinum was announced for sale on December 20.[6][1] The Platinum Pro followed on January 13, 2025, with a workflow that the company describes as combining sample preparation, sequencing and data analysis in one system.[2][3]
Technology
The method reads the N-terminus, the end of a peptide that carries a free amino group, and it uses two sets of molecules together. Recognizers are dye-labeled molecules that bind to the amino acid at the terminus. Aminopeptidases are enzymes that remove the terminal amino acid and leave the next one exposed.[6] The cycle is the one that Edman degradation has used since 1950, with an enzyme doing the chemistry and a recognizer doing the identification.[7]
Each binding event shows up as a pulse of fluorescence. The paper identifies amino acids from three properties of the signal: the intensity of the fluorescence, its lifetime (how long the dye glows after it is excited), and the binding kinetics, meaning how long a recognizer stays on and how often it returns.[6] The kinetics matter because a recognizer does not have to be specific to one amino acid. One that binds several can still tell them apart by how long it dwells on each, and the authors report that the same behavior distinguishes single amino acid substitutions and post-translational modifications.[6][8] Light is collected by an integrated semiconductor device, which a news report on the paper says contains millions of wells.[8]
The instrument reads peptides, so a sample goes through library preparation before it reaches the chip.[3] Nanopore methods read the unlabeled chain by its effect on an ionic current, as Nanopore protein sequencing describes. Nautilus Biotechnology takes a third route, in which single intact proteins fixed on an array are identified by the pattern in which affinity reagents bind them.[9]
Products
The Platinum Pro is sold as "a compact benchtop system" with library preparation kits, sequencing kits holding the chips, recognizers and aminopeptidases, and barcoding kits for characterizing several protein variants at once. The company says that its library preparation works from 200 nanograms of protein or less.[3] The product page also carries the line "RESEARCH USE ONLY. NOT FOR USE IN DIAGNOSTIC PROCEDURES."[3]
Relationship with Molecular Reality
The Hole World, the atlas of molecular-sensing groups kept by Molecular Reality Corporation, singles out 38 entries as flagships and draws each with a hand-written caption. Quantum-Si's is "Protein sequencing chip".[10]
See also
References
- ^ a b "Quantum-Si announces commercial availability of Platinum, the world's first next-generation single-molecule protein sequencing platform" (Press release). Quantum-Si. December 20, 2022. Retrieved October 25, 2026.
- ^ a b "Quantum-Si launches Platinum Pro: the end-to-end solution for deeper insights in proteomics" (Press release). Quantum-Si. January 13, 2025. Retrieved October 25, 2026.
- ^ a b c d e "Products". Quantum-Si. Retrieved October 25, 2026.
- ^ "Jonathan Rothberg, PhD". Yale School of Medicine. Retrieved October 25, 2026.
- ^ "Form 10-K for the fiscal year ended December 31, 2024". Quantum-Si Incorporated, U.S. Securities and Exchange Commission. 2025. Retrieved October 25, 2026.
- ^ a b c d Reed, B. D.; Meyer, M. J.; Abramzon, V.; et al. (2022). "Real-time dynamic single-molecule protein sequencing on an integrated semiconductor device". Science 378 (6616): 186-192. doi:10.1126/science.abo7651. PMID 36227977.
- ^ Edman, P.; et al. (1950). "Method for determination of the amino acid sequence in peptides". Acta Chemica Scandinavica 4: 283-293. doi:10.3891/acta.chem.scand.04-0283.
- ^ a b "Semiconductor chip sequences single proteins". Genetic Engineering and Biotechnology News. October 14, 2022.
- ^ "Nautilus Proteome Analysis Platform". Nautilus Biotechnology. Retrieved October 25, 2026.
- ^ "The Hole World: build metadata". Molecular Reality Corporation. September 26, 2026.