13D Filing: Casdin Capital and Genmark Diagnostics Inc. (GNMK)

Eli Casdin

Casdin Capital, LLC

1350 Avenue of the Americas, Suite 2405

New York, New York

Telephone Number (212) 897-5438

(Name, Address and Telephone Number of Person
Authorized to Receive

Notices and Communications)

The Reporting Persons have acquired their Shares
of the Issuer for investment. The Reporting Persons have no plans or proposals as of the date of this filing which, other than
as expressly set forth below, would relate to or would result in: (a) any extraordinary corporate transaction involving the Issuer;
(b) any change in the present Board of Directors or management of the Issuer; (c) any material change in the present capitalization
or dividend policy of the Issuer; (d) any material change in the operating policies or corporate structure of the Issuer; (e) any
change in the Issuer’s charter or by-laws; (f) the Shares of the Issuer ceasing to be listed from a national securities exchange
or to ceasing to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association;
or (g) causing the Issuer becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Securities Exchange
Act of 1934.

The Reporting Persons, however, reserve the
right, at a later date, to effect one or more of such changes and may dispose of or enter into other transactions in the shares
they may be deemed to beneficially own.

The Reporting Persons have been and may continue
to be in contact with members of the Issuer’s management, the Issuer’s Board of Directors, other significant shareholders and others
regarding alternatives that the Issuer could employ to maximize shareholder value.

The Reporting Persons further reserve the right
to act in concert with any other shareholders of the Issuer, or other persons, for a common purpose should it determine to do so,
and/or to recommend courses of action to management and the shareholders of the Issuer.

As of the date hereof, the Reporting Persons
may be deemed to be the beneficial owners of 3,850,000 Shares, constituting 7.0% of the Shares, based upon 55,166,687* Shares outstanding.

Casdin has the sole power to vote or direct
the vote of 0 Shares; has the shared power to vote or direct the vote of 3,850,000 Shares; has the sole power to dispose or direct
the disposition of 0 Shares; and has the shared power to dispose or direct the disposition of 3,850,000 Shares.

The Fund has the sole power to vote or direct
the vote of 0 Shares; has the shared power to vote or direct the vote of 3,850,000 Shares; has the sole power to dispose or direct
the disposition of 0 Shares; and has the shared power to dispose or direct the disposition of 3,850,000 Shares.

The GP has the sole power to vote or direct
the vote of 0 Shares; has the shared power to vote or direct the vote of 3,850,000 Shares; has the sole power to dispose or direct
the disposition of 0 Shares; and has the shared power to dispose or direct the disposition of 3,850,000 Shares.

Eli Casdin has the sole power to vote or direct
the vote of 0 Shares; has the shared power to vote or direct the vote of 3,850,000 Shares; has the sole power to dispose or direct
the disposition of 0 Shares; and has the shared power to dispose or direct the disposition of 3,850,000 Shares.

The transactions by the Reporting Persons in
the Shares during the past sixty days are set forth in Exhibit B. All such transactions were carried out in open market transactions.

*This outstanding Shares figure reflects the
number of outstanding Shares at February 23, 2018, as reported in the Form 10-K filed by the Issuer on February 27, 2018.

Exhibit A: Joint Filing Agreement

Exhibit B: Schedule of Transactions in Shares

Casdin Capital, LLC*

By: /s/ Eli Casdin

Casdin Partners Master Fund, L.P.

By: Casdin Partners GP, LLC, its general partner

By: /s/ Eli Casdin

Casdin Partners GP, LLC*

By: /s/ Eli Casdin

Casdin Capital, LLC

By: /s/ Eli Casdin

Casdin Partners Master Fund, L.P.

By: Casdin Partners GP, LLC, its general partner

By: /s/ Eli Casdin

Casdin Partners GP, LLC

By: /s/ Eli Casdin

Date of Transaction

Title of Class

Price Per

Share*