Important Additional Information and Where to Find It
In connection with the transactions, Repligen will file with the SEC a registration statement on Form S-4 (the
“registration statement”), which will contain a proxy statement of BioLife and a prospectus of Repligen (the “proxy statement/prospectus”), and each of Repligen and BioLife may file with the SEC other relevant
documents regarding the transactions. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT AND THE PROXY STATEMENT/PROSPECTUS CAREFULLY AND IN THEIR ENTIRETY AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC BY REPLIGEN AND
BIOLIFE, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THOSE DOCUMENTS WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT REPLIGEN, BIOLIFE AND THE transactions. When final, a definitive copy of the proxy
statement/prospectus will be mailed to BioLife stockholders. Investors and security holders will be able to obtain the registration statement and the proxy statement/prospectus, as well as other filings containing information about Repligen and
BioLife, free of charge from Repligen or BioLife or from the SEC’s website when they are filed. The documents filed by Repligen with the SEC may be obtained free of charge at Repligen’s website, at www.repligen.com, or by
requesting them by mail at Repligen Corporation, 41 Seyon Street Building 1, Suite 100 Waltham, Massachusetts 02453, Attention: Corporate Secretary. The documents filed by BioLife with the SEC may be obtained free of charge at BioLife’s
website, at www. biolifesolutions.com, or by requesting them by mail at BioLife Solutions, Inc., 3303 Monte Villa Parkway, Suite 310, Bothell, WA 98021, Attention: Corporate Secretary. The information included on Repligen’s and
BioLife’s websites is not incorporated by reference into this communication.
Participants in the Solicitation
Repligen and BioLife and certain of their respective directors and executive officers may be deemed to be participants in the solicitation of proxies from the
stockholders of BioLife in respect of the transactions. Information about Repligen’s directors and executive officers is available in Repligen’s proxy statement, dated April 2, 2026, for its 2026 Annual Meeting of Stockholders, and
other documents filed by Repligen with the SEC. Information about BioLife’s directors and executive officers is available in BioLife’s proxy statement, dated July 8, 2025, for its 2025 Annual Meeting of Stockholders, and other
documents filed by BioLife with the SEC. Other information regarding the persons who may, under the rules of the SEC, be deemed participants in the proxy solicitation and a description of their direct and indirect interests, by security holdings or
otherwise, will be contained in the proxy statement/prospectus and other relevant materials to be filed with the SEC regarding the transactions when they become available. Investors should read the proxy statement/prospectus carefully when it
becomes available before making any voting or investment decisions. You may obtain free copies of these documents from Repligen or BioLife as indicated above.
No Offer or Solicitation
This communication is not
intended to and shall not constitute an offer to sell or the solicitation of an offer to buy any securities, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to
registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act.