Exhibit 5.1

Karen E. Deschaine

+1 858 550 6088

kdeschaine@cooley.com

February 17, 2021

Talis Biomedical Corporation

230 Constitution Drive

Menlo Park, California 94025

Ladies and Gentlemen:

We have represented Talis Biomedical Corporation, a Delaware corporation (the “Company”), in connection with the filing by the Company of a registration statement on Form S-8 (the “Registration Statement”) with the Securities and Exchange Commission, covering the offering of up to 13,390,904 shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (the “Common Stock”), consisting of (i) 7,673,915 shares of Common Stock issuable pursuant to the Company’s 2013 Equity Incentive Plan, as amended (the “Prior Plan”), (ii) 5,166,989 shares of Common Stock issuable pursuant to the Company’s 2021 Equity Incentive Plan (the “2021 Plan”), and (iii) 550,000 shares of Common Stock issuable pursuant to the Company’s 2021 Employee Stock Purchase Plan (together with the Prior Plan and the 2021 Plan, the “Plans”).

In connection with this opinion, we have examined and relied upon (i) the Registration Statement and related prospectuses, (ii) the Company’s Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws, each as currently in effect, (iii) the Plans, and (iv) originals or copies certified to our satisfaction of such records, documents, certificates, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies, the accuracy, completeness and authenticity of certificates of public officials and the due execution and delivery of all documents by all persons other than the Company where execution and delivery are a prerequisite to the effectiveness thereof. As to certain factual matters, we have relied upon a certificate of an officer of the Company and have not independently verified such matters.

Our opinion is expressed only with respect to the General Corporation Law of the State of Delaware. We express no opinion to the extent that any other laws are applicable to the subject matter hereof and express no opinion and provide no assurance as to compliance with any federal or state securities law, rule or regulation.

Cooley LLP    4401 Eastgate Mall    San Diego, CA    92121

t: (858) 550-6000    f: (858) 550-6420    cooley.com

February 17, 2021

Page Two

On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares, when sold and issued against payment therefor as described in the Registration Statement and related prospectuses, will be validly issued, fully paid and non-assessable (except as to shares issued pursuant to certain deferred payment arrangements, which will be fully paid and nonassessable when such deferred payments are made in full).

We consent to the filing of this opinion as an exhibit to the Registration Statement.

Sincerely,

Cooley LLP
By:	/s/ Karen E. Deschaine
	Karen E. Deschaine

Cooley LLP    4401 Eastgate Mall    San Diego, CA    92121

t: (858) 550-6000    f: (858) 550-6420    cooley.com