SEC Form 3

FORM 3

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

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1. Name and Address of Reporting Person* DEKKERS MARIJN E (Last) (First) (Middle) C/O QUANTERIX CORPORATION, 113 HARTWELL AVENUE (Street) LEXINGTON MA 02421 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 12/06/2017	3. Issuer Name and Ticker or Trading Symbol Quanterix Corp [ QTRX ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) Other (specify below)	5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series D-1 Preferred Stock	(1)	(2)	Common Stock	77,378	(3)	D
Stock Option (right to buy)	(4)	03/31/2027	Common Stock	31,113(5)	$8.16(5)	D

Explanation of Responses:

1. These shares are convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election.

2. Not applicable.

3. The shares of preferred stock will convert into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock will convert on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security.

4. The option vests as to 25% of the shares on March 13, 2018 and vests as to an additional 2.083% of the shares per month thereafter until February 28, 2021.

5. Reflects the 1-for-3.214 reverse stock split of the Issuer's common stock effected on December 4, 2017 in connection with the Issuer's initial public offering, pursuant to which (i) the number of shares of common stock underlying the option was divided by 3.214 and (ii) the exercise price of the option was multiplied by 3.214.

Remarks:

Exhibit 24.1 - Power of Attorney

	/s/ Brian Keane, Attorney-in-fact	12/06/2017
	** 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 5 (b)(v).
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