Quantum-Si Announces the Launch of V4 Sequencing Kit, Expanding Proteome Coverage and Unlocking New Applications for Protein Sequencing

Quantum-Si Incorporated (Nasdaq: QSI) ("Quantum-Si," "QSI" or the "Company"), a proteomics technology company redefining protein analysis through single-molecule detection, today announced the launch of the V4 Sequencing Kit. The new kit is compatible with both the Platinum ^® and Platinum ^® Pro instruments.

The V4 Sequencing Kit improves sequencing coverage with the addition of glycine (G) recognition, enhanced alanine (A) and serine (S) recognition, an enzyme designed to cut through the amino acid directly proceeding proline (P), and new algorithms to improve precision and mixture handling.

Key Advancements & Applications Enabled:

• Sequence Beyond Proline – V4 Sequencing Kit enables the analysis of proline-rich domains common in antibodies and membrane proteins.
• Expanded Amino Acid Coverage – New recognizers, enzyme and improved bioinformatics offers an 85% increase in sequenceable peptides compared to the V3 Sequencing Kit.
• Sample Mixture Precision – Expanded coverage and improved bioinformatics enables barcoding of up to 24-plex and improved analysis of protein mixtures common in immunoprecipitation workflows.

"The performance of the V4 Sequencing Kit is a significant leap forward over the prior version of our chemistry and will open up new applications such as antibody sequencing and expand the range of complex mixtures customers can analyze," said Jeff Hawkins, President and Chief Executive Officer of Quantum-Si. "In addition, as part of this version 4 sequencing kit release, we are enabling our barcoding customers to capture further cost savings with an expanded set of 24 barcodes without sacrificing on analytical performance."

To learn more visit: https://www.quantum-si.com/seq-kit/

About Quantum-Si Incorporated

Quantum-Si is transforming proteomics with a benchtop platform that brings single-molecule protein analysis to every lab, everywhere. The Company's platform enables real-time kinetic-based detection and allows researchers to move beyond traditional, multistep workflows and directly access dynamic, functional protein insights with unparalleled resolution. By making protein analysis simpler, faster, and more informative, Quantum-Si is accelerating proteomic discoveries to improve the way we live. Learn more at quantum-si.com or follow us on LinkedIn or X .

Forward Looking Statements

This press release includes "forward-looking statements" within the meaning of the "safe harbor" provisions of the United States Private Securities Litigation Reform Act of 1995. The actual results of the Company may differ from its expectations, estimates, and projections and, consequently, you should not rely on these forward-looking statements as predictions of future events. Words such as "expect," "estimate," "project," "budget," "forecast," "anticipate," "intend," "plan," "may," "will," "could," "should," "believes," "predicts," "potential," "continue," and similar expressions (or the negative versions of such words or expressions) are intended to identify such forward-looking statements. These forward-looking statements include, without limitation, the Company's expectations with respect to future performance and development and commercialization of products and services, its anticipated cash runway, anticipated data and product launches, investor confidence in Quantum-Si and our strategic roadmap, and any financial guidance for 2025. These forward-looking statements involve significant risks and uncertainties that could cause the actual results to differ materially from those discussed in the forward-looking statements. Most of these factors are outside the Company's control and are difficult to predict. Factors that may cause such differences include, but are not limited to: the inability to maintain the listing of the Company's Class A common stock on The Nasdaq Stock Market; the ability of the Company to grow and manage growth profitably and retain its key employees; the Company's ongoing leadership transitions; changes in applicable laws or regulations; the ability of the Company to raise financing in the future; the success, cost and timing of the Company's product development and commercialization activities, including the use and benefit of artificial intelligence in these and other activities; the commercialization and adoption of the Company's existing products and the success of any product the Company may offer in the future; the potential attributes and benefits of the Company's commercialized Platinum® protein sequencing instruments and kits and the Company's other products once commercialized; the Company's ability to obtain and maintain regulatory approval for its products, and any related restrictions and limitations of any approved product; the Company's ability to identify, in-license or acquire additional technology; the Company's ability to maintain its existing lease, license, manufacture and supply agreements; the Company's ability to compete with other companies currently marketing or engaged in the development or commercialization of products and services that serve customers engaged in proteomic analysis, many of which have greater financial and marketing resources than the Company; the size and growth potential of the markets for the Company's products and services, and its ability to serve those markets once commercialized, either alone or in partnership with others; the Company's estimates regarding future expenses, future revenue, capital requirements and needs for additional financing; the Company's financial performance; and other risks and uncertainties described under "Risk Factors" in the Company's most recent Annual Report on Form 10-K and Quarterly Reports on Form 10-Q and in the Company's other filings with the SEC. The Company cautions that the foregoing list of factors is not exclusive. The Company cautions readers not to place undue reliance upon any forward-looking statements, which speak only as of the date made. The Company does not undertake or accept any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements to reflect any change in its expectations or any change in events, conditions, or circumstances on which any such statement is based.

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ir@quantum-si.com