EXPLANATORY NOTE
This Registration Statement on Form S-8 is filed by Pacific Biosciences of California, Inc. (the
Company) in connection with the Agreement and Plan of Merger and Reorganization (the Merger Agreement), dated as of July 19, 2021, by and among the Company, Apollo Acquisition Corp. (Merger Sub I), Apollo
Acquisition Sub, LLC (Merger Sub II), Omniome, Inc. (Omniome), and Shareholder Representative Services LLC. Pursuant to the Merger Agreement, on September 20, 2021 (the Effective Time), Merger Sub I merged
with and into Omniome, with Omniome surviving as a wholly owned subsidiary of the Company (the First Merger). Subsequent to the First Merger, Omniome merged with and into Merger Sub II, with Merger Sub II continuing as a wholly owned
subsidiary of the Company.
Under the Merger Agreement, each unvested option to purchase Omniome common stock granted under the Omniome, Inc. 2014 Equity
Incentive Plan (the Omniome Plan) held by employees continuing with the Company were assumed by the Company (the Assumed Options) and converted into an option to purchase shares of the Companys common stock, on
substantially the same terms and conditions (including vesting and exercisability), except that (A) the Assumed Options will cover shares of the Companys common stock; (B) the number of shares of Companys common stock subject
to the Assumed Option will be equal to the product of (i) the number of shares of Omniome common stock subject to the corresponding unvested option, multiplied by (ii) the exchange ratio (as defined below), with any resulting fractional
share rounded down to the nearest whole share; and (C) the exercise price per share of the Assumed Options will be equal to the quotient of (i) the exercise price per share of the corresponding unvested option to purchase shares of Omniome
common stock, divided by (ii) the exchange ratio (as defined below), with any resulting fractional cent rounded up to the nearest whole cent.
The
exchange ratio is equal to $0.257166378, which is the quotient obtained by dividing $7.483542 by $29.10, the volume weighted average of the trading prices of the shares of the Companys common stock on Nasdaq (as reported by
Bloomberg, or, if not available, any other authoritative source), for the ten consecutive trading days ending with, and including, the trading day immediately before the Effective Time.
This Registration Statement is being filed for the purpose of registering 844,336 shares of the Companys common stock subject to outstanding unvested
options assumed by the Registrant, as adjusted based on the exchange ratio and converted into unvested options to purchase shares of the Companys common stock in accordance with the Merger Agreement, and 1,649,792 shares of the Companys
common stock available for future issuance under the Omniome Equity Incentive Plan of Pacific Biosciences of California, Inc., which shares represent the number of shares of common stock of Omniome that were available for issuance under the Omniome
Plan, as adjusted based on the exchange ratio pursuant to the Merger Agreement, and converted into shares of the Companys common stock.