Sec Form 3 Filing - Northpond Capital GP, LLC @ IsoPlexis Corp - 2021-10-07

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Northpond Capital GP, LLC 2. Issuer Name and Ticker or Trading Symbol IsoPlexis Corp [ ISO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 7500 OLD GEORGETOWN ROAD, SUITE 850 3. Date of Earliest Transaction (MM/DD/YY) 10/07/2021 (Street) BETHESDA, MD20814 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Series C Redeemable Convertible Preferred Stock ( 1 ) ( 1 ) ( 1 ) Common Stock 2,302,280 I See footnote ( 2 ) Series C-2 Redeemable Convertible Preferred Stock ( 1 ) ( 1 ) ( 1 ) Common Stock 2,473,048 I See footnote ( 2 ) Series D Redeemable Convertible Preferred Stock ( 1 ) ( 1 ) ( 1 ) Common Stock 1,528,864 I See footnote ( 2 ) Series D Redeemable Convertible Preferred Stock ( 1 ) ( 1 ) ( 1 ) Common Stock 1,040,048 I See footnote ( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Northpond Capital GP, LLC 7500 OLD GEORGETOWN ROAD SUITE 850 BETHESDA, MD20814 X Northpond Capital, L.P. 7500 OLD GEORGETOWN ROAD SUITE 850 BETHESDA, MD20814 X Northpond Ventures GP, LLC 7500 OLD GEORGETOWN ROAD SUITE 850 BETHESDA, MD20814 X Northpond Ventures, LP 7500 OLD GEORGETOWN ROAD SUITE 850 BETHESDA, MD20814 X Rubin Michael P. C/O NORTHPOND VENTURES 7500 OLD GEORGETOWN ROAD, SUITE 850 BETHESDA, MD20814 X Signatures Northpond Capital GP, LLC, By: /s/ Patrick Smerkers, Senior Vice President, Finance and Operations 10/07/2021 Signature of Reporting Person Date Northpond Capital, LP, By: Northpond Capital GP, LLC, its general partner, By: /s/ Patrick Smerkers, Senior Vice President, Finance and Operations 10/07/2021 Signature of Reporting Person Date Northpond Ventures GP, LLC, By: /s/ Patrick Smerkers, Senior Vice President, Finance and Operations 10/07/2021 Signature of Reporting Person Date Northpond Ventures, LP, By: Northpond Ventures GP, LLC, its general partner, By: /s/ Patrick Smerkers, Senior Vice President, Finance and Operations 10/07/2021 Signature of Reporting Person Date /s/ Michael P. Rubin 10/07/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each share of the Series C Redeemable Convertible Preferred Stock, Series C-2 Redeemable Convertible Preferred Stock and Series D Redeemable Convertible Preferred Stock is convertible at any time, at the Reporting Persons' election, on a one-for-8 basis, and will convert automatically upon the Issuer's consummation of an initial public offering. The number of shares held is shown on an as-converted to common stock basis. The preferred stock has no expiration date. ( 2 )The securities are held directly by Northpond Ventures, LP ("Northpond"). Northpond Ventures GP, LLC ("Northpond GP") is the general partner of Northpond. Michael P. Rubin ("Rubin") is the managing member of Northpond GP. ( 3 )The securities are held directly by Northpond Capital, LP ("Northpond Capital"). Northpond Capital GP, LLC ("Northpond Capital GP") is the general partner of Northpond Capital. Rubin is the managing member of Northpond Capital GP.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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