Biocept (BIOCQ) 8-K Changes in Registrant's Certifying Accountant

Exhibit 16.1

April 11, 2022

Securities and Exchange Commission

100 F Street N.E.

Washington, D.C. 20549

Commissioners:

We have read Item 4.01 of Biocept, Inc.’s Form 8-K dated April 11, 2022, and we agree with the statements set forth in Item 4.01, insofar as they relate to our firm. We have no basis to agree or disagree with other statements made by the registrant contained in Item 4.01.

Very truly yours,

/s/ Mayer Hoffman McCann P.C.

San Diego, California