SEC Form 4

FORM 4		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 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* CRANDELL KEITH (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Quanterix Corp [ QTRX ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 10/01/2021
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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
Common Stock	08/10/2021		J(1)		189,311	D	$0.00	555,869	I	See Footnote(2)
Common Stock	08/10/2021		J(1)		120,689	D	$0.00	354,381	I	See Footnote(3)
Common Stock	08/10/2021		J(1)(4)		9,952	A	$0.00	85,804	D
Common Stock	08/17/2021		J(1)		189,311	D	$0.00	366,558	I	See Footnote(2)
Common Stock	08/17/2021		J(1)		120,689	D	$0.00	233,692	I	See Footnote(3)
Common Stock	08/17/2021		J(1)(4)		9,954	A	$0.00	95,758	D
Common Stock	10/01/2021		A		254(5)	A	$51.18(6)	96,012(7)	D

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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. Distribution of Common Stock held by a limited partnership to its partners for no consideration.

2. These shares are directly held by ARCH Venture Fund VI, L.P. ("ARCH VI"). ARCH Venture Partners VI, L.P. ("GPLP"), the sole general partner of ARCH VI, may be deemed to beneficially own the shares held by ARCH VI. ARCH Venture Partners VI, LLC ("GPLLC"), as the sole general partner of GPLP, may be deemed to beneficially own the shares held by ARCH VI. The Reporting Person is a managing director of the GPLLC and shares voting and investment control with respect to these shares. The Reporting Person may be deemed to beneficially own the shares held by ARCH VI. The Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of his pecuniary interest therein, if any.

3. These shares are directly held by ARCH Venture Fund VIII Overage, L.P. ("ARCH Overage"). ARCH Venture Partners VIII, LLC ("ARCH VIII LLC") the sole general partner of ARCH Overage, may be deemed to beneficially own the shares held by ARCH Overage. The Reporting Person is a managing director of the ARCH VIII LLC and shares voting and investment control with respect to these shares. The Reporting Person may be deemed to beneficially own the shares held by ARCH Overage. The Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of his pecuniary interest therein, if any.

4. Change from indirect to direct ownership of shares previously reported as beneficially owned by the Reporting Person.

5. Consists of stock granted in lieu of cash fees for service on the Company's Board of Directors and committees thereof for the third quarter of 2021.

6. Closing price of the Company's common stock on the Nasdaq Global Market on October 1, 2021.

7. Includes 2,270 restricted stock units.

Remarks:

	/s/ Brian Keane, as Attorney-in-Fact for Keith L. Crandell	10/05/2021
	** Signature of Reporting Person	Date
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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