Exercise of Over-allotment Option

Abcam plc

THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF REGULATION (EU) NO 596/2014

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, IN WHOLE OR IN PART, IN OR INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION

Abcam Announces Exercise of Over-allotment Option

October 23, 2020, LONDON - Abcam plc (AIM: ABC) (NASDAQ: ABCM) ("Abcam"), a global leader in the supply of life science research tools, announces that the underwriters of its offering of American Depositary Shares ("ADSs")(the "Offering"), have given notice to Abcam that they are exercising their over-allotment option. The underwriters have elected to purchase an additional 1,341,782 ADSs at the Offering price of $17.50 per ADS, raising approximately an additional $23.5 million in gross proceeds for Abcam and bringing the total gross proceeds of the Offering to approximately $180.0 million. Closing of the exercise of the over-allotment option is expected to occur on October 26, 2020, subject to customary closing conditions.

All of the ADSs in the Offering were sold by Abcam and are trading on the NASDAQ Global Market under the ticker symbol "ABCM". Abcam's ordinary shares are admitted to trading on the AIM market of the London Stock Exchange ("AIM") under the symbol "ABC". Each ADS represents one ordinary share of Abcam.

Morgan Stanley and BofA Securities acted as the lead book-running managers for the Offering. SVB Leerink acted as a book-running manager, and Lazard and William Blair acted as co-managers.

A registration statement relating to these securities was declared effective by the Securities and Exchange Commission on October 21, 2020. The Offering was made only by means of a prospectus. Copies of the final prospectus relating to and describing the terms of the Offering may be obtained from the offices of Morgan Stanley, Attention: Prospectus Department, 180 Varick Street, 2nd Floor, New York, New York 10014; or from BofA Securities, Attention: Prospectus Department, 200 North College Street, 3rd Floor, Charlotte, North Carolina 28255-0001, or by email at [email protected].

This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of, these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of such state or jurisdiction.

For readers in the European Economic Area and the United Kingdom

There will be no public offer of the ADSs to the public in the European Economic Area or the United Kingdom.

This communication , in so far as it constitutes an invitation or inducement to enter into investment activity within the meaning of section 21 of the Financial Services and Markets Act 2000 as amended ("FSMA") in connection with the securities which are the subject of the offering described in this press release or otherwise, is only being directed at: (a) in the European Economic Area (the "EEA"), persons who are qualified investors within the meaning of Article 2(e) of Prospectus Regulation (EU) 2017/1129 (the "Prospectus Regulation") ("Qualified Investors"); and (b) in the United Kingdom, Qualified Investors who are (i) persons who fall within the definition of "Investment Professionals" in Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended (the "Order"); or (ii) persons who fall within Article 49(2)(a) to (d) ("High net worth companies, unincorporated associations etc.") of the Order; or (c) persons to whom it may otherwise be lawfully communicated (all such persons referred to in (a), (b) and (c) above together being referred to as "Relevant Persons").

The ADSs offered in the Offering are only available to, and any invitation, offer or agreement to subscribe, purchase or otherwise acquire such ADSs will be engaged in only with, in the EEA and the United Kingdom, Relevant Persons. Any person who, in the EEA or the United Kingdom, is not a Relevant Person should not act or rely on this document or any of its contents. This communication does not contain an offer or constitute any part of an offer to the public within the meaning of sections 85 and 102B of FSMA or otherwise.

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