Pacific Biosciences of California (PACB) 8-K Changes in Registrant's Certifying Accountant

Exhibit 16.1

June 21, 2011

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

Commissioners:

We have read the statements made by Pacific Biosciences of California, Inc. (copy attached), which we understand will be filed with the Securities and Exchange Commission, pursuant to Item 4.01 of Form 8-K, as part of the Form 8-K of Pacific Biosciences of California, Inc. dated June 16, 2011. We agree with the statements concerning our Firm in such Form 8-K.

Very truly yours,

/s/ PricewaterhouseCoopers LLP