United States securities and exchange commission logo





                              April 27, 2021

       Daniel Jones
       Chief Executive Officer
       SeqLL Inc.
       317 New Boston Street, Suite 210
       Woburn, Massachusetts 01801

                                                        Re: SeqLL Inc.
                                                            Registration
Statement on Form S-1
                                                            Filed March 31,
2021
                                                            File No. 333-254886

       Dear Mr. Jones:

              We have reviewed your registration statement and have the
following comments. In
       some of our comments, we may ask you to provide us with information so
we may better
       understand your disclosure.

              Please respond to this letter by amending your registration
statement and providing the
       requested information. If you do not believe our comments apply to your
facts and
       circumstances or do not believe an amendment is appropriate, please tell
us why in your
       response.

              After reviewing any amendment to your registration statement and
the information you
       provide in response to these comments, we may have additional comments.

       Registration Statement on Form S-1, Filed March 31, 2021

       Summary, page 1

   1.                                                   Please revise this
section to clarify your current operations, including the products and
                                                        services you are
selling, years of sales and geographical distribution.
   2.                                                   Given the extensive
disclosure regarding the benefits of your product relative to
                                                        competing products,
please explain the reasons for your current level of sales and share of
                                                        the market in which you
compete.
   3.                                                   On pages 5-6 you state
that your technology could be used as a companion diagnostic in
                                                        clinical trials, or to
diagnose disease. Please clarify the FDA approval status or whether
                                                        you intend to seek FDA
approval in the future for any products. Clarify which strategies
                                                        will require regulatory
approval.
 Daniel Jones
FirstName
SeqLL Inc.LastNameDaniel Jones
Comapany
April       NameSeqLL Inc.
       27, 2021
April 227, 2021 Page 2
Page
FirstName LastName
4.       Highlight in an appropriate section of your prospectus summary that
you intend to raise
         additional funds following the completion of this offering and that
your ability to continue
         to operate is dependent upon the success of this offering, as you
disclose on page 45.
5.       We note your disclosure on page 1 that data produced by your tSMS
platform generates
         highly accurate, reproducible molecular profiles, often providing
researchers with new
         insights into the biology being researched, such as revealing
previously unknown
         characteristics of molecular structures. We also note your disclosure
on page 5 that you
         provide solutions for a variety of applications, including genome
structural analysis.
          While it seems to be clear from your disclosure how your sequencing
technology works,
         please clarify how your platform reveals previously unknown
characteristics of molecular
         structures and provides genome structural analysis, and clarify
whether this feature is
         available in the platform that you currently offer. For example, we
note from your
         disclosure under    Our Customers and Collaborations    on page 7 that
some of these
         technologies may be part of new prototype systems that you intend to
make available to
         some of your collaborators on an early-access basis in the second half
of 2021, and it is
         unclear whether some of this technology refers to the work being
performed by the Broad
         Institute based on anti-body based detection coupled-with your system,
or otherwise.
6.       We note from your disclosure that Figure 1 is intended to show
antibody-detection
         reactions but Figure 1 does not appear to show that part of the
workflow. Please revise as
         appropriate.
Our Strategy, page 6

7.       We note your disclosure that you "generate revenues through a
combination of product
         sales, research services and research grants." Please balance this
disclosure by indicating
         that the company recognized $0 and $2,000 in revenue from product
sales for the years
         ended December 31, 2020 and 2019, respectively, as indicated on page
F-9.
Our Customers and Collaborators, page 7

8.       Please revise pages 7-8 to clarify whether you are selling products or
services to these
         entities or collaborating with them pursuant to an agreement. If the
former, please ensure
         the products and/or services are described for each entity. If the
latter, please describe the
         material terms of the agreements and file the agreements as exhibits
pursuant to Item
         601(b)(10) of Regulation S-K.
Risk Factors, page 14

9.       If true, please add a risk factor disclosing that your CEO and William
C. St Laurent will
         beneficially control a majority of the voting power of your
outstanding common stock,
         and as a result, will be able to determine the outcome of future
corporate actions including
         the election of directors. Please clarify the percentage that will be
held by insiders if an
         anchor investor insider purchased additional shares in this offering,
as indicated on the
         cover.
 Daniel Jones
FirstName
SeqLL Inc.LastNameDaniel Jones
Comapany
April       NameSeqLL Inc.
       27, 2021
April 327, 2021 Page 3
Page
FirstName LastName
10.      Please include risk factor disclosure concerning the bankruptcy of
Helicos, who appears to
         have attempted to develop and commercialize a version of the
technology you are
         developing today, or advise.
Dilution, page 42

11.      In the second paragraph it appears that you have presented your pro
forma net tangible
         book value (deficit) as your historical net tangible book value
(deficit). Please revise to
         present historical net tangible book value (deficit) separately from
pro forma net tangible
         book value (deficit) which gives effect to the conversion of all
outstanding shares of
         preferred stock and the conversion of outstanding indebtedness.
Management's Discussion and Analysis of Financial Condition and Results of
Operations
Comparison of Years Ended December 31, 2020 and 2019, page 46

12.      We note your disclosure that your research and development expenses
and general and
         administrative expenses decreased in 2020 as compared to 2019 due to
the COVID-
         19 pandemic-related reductions, salary reductions, furloughs and
reduced spending. If
         these expenses will increase in 2021, please describe any known trends
or uncertainties
         that are reasonably likely to have a material impact on your income or
losses from
         continuing operations. Refer to Item 303(b)(2)(ii) of Regulation S-K.
Critical Accounting Policies and Estimates
Revenue Recognition, page 50

13.      We note the revenue recognition policy on page 50 related to the sale
of products and
         services. Given the description of the components of your tSMS single
molecule
         sequencing platform on pages 60-61, i.e., consumables, sample loader,
tSMS sequencer
         and image analysis engine, please clarify herein and in the
significant accounting
         policy on page F-9 whether any of the foregoing components can be
purchased and/or
         effectively utilized apart from one another. If so, please explain how
and/or under what
         circumstances. Explain whether service revenue, i.e., genetic
sequencing involved with
         research services and associated bioinformatics specialist support,
can be purchased
         and/or effectively utilized apart from the foregoing tSMS single
molecule
         sequencing components. Finally, if there is no binding agreement or
requirement to
         purchase the components and/or services together - and so can be used
without each other
         - clarify how this impacts your determination of your performance
obligations.
Our Technology Solution, page 55

14.      We note your disclosure under the heading "Minimal Sample Preparation"
appears to be
         based on data from 2012 and your disclosure under the heading "Greater
Sensitivity"
         appears to be based on data from 2011. Please tell us if this data
continues to be reliable
         or if more recent data is available. If this data does not accurately
represent the current
         state-of-the-art of your competitor's products, please revise or
remove these comparisons
 Daniel Jones
SeqLL Inc.
April 27, 2021
Page 4
         as appropriate.
Intellectual Property, page 68

15.      On page 25 you state that you license or sub-license intellectual
property that is important
         to your business from Fluidigm Corporation and Arizona Science and
Technology
         Enterprises LLC. Please revise to provide a description of the
agreements and file these
         agreements as exhibits.
Management, page 70

16.      Please provide the Compensation Committee Interlocks and Insider
Participation
         information required by Item 407(e)(4).
Executive Compensation, page 76

17.      Page F-13 indicates stock options are outstanding as of December 31,
2020. Please revise
         this section to provide the information required by Item 402(p) of
Regulation S-K to the
         extent applicable.
Principal Stockholders, page 81

18.      Please revise your disclosure to identify the natural person or
persons who have voting
         and/or investment control of the shares held by the Georges C. St.
Laurent Jr. Trust. Refer
         to Item 403 of Regulation S-K.
Certain Relationships and Related Party Transactions, page 83

19.      We note your statement on page 84 that the principal on the Georges C.
St. Laurent Jr.
         Trust promissory note will convert on the closing of this offering and
the accrued interest
         will be paid out of the cash proceeds. Please state the amount of
shares that the Georges C.
         St. Laurent Jr. Trust promissory note principal will convert into upon
the closing of this
         offering. Please also reconcile this disclosure with page 37, where
you state you will repay
         a to-be-provided amount in principal amount of outstanding promissory
notes that bear
         interest at the rate of 10% per annum and related accrued interest
given these appear to be
         the same promissory note, or clarify that they are different notes.
20.      We note the related party payables chart on page F-13. Please revise
this section to
         describe the arrangements between the Company and each of these
entities associated
         with William C. St. Laurent.
Description of Capital Stock,Jones
FirstName LastNameDaniel      page 85
Comapany
21.        NameSeqLL
       Please             Inc. the number of shares with registration rights
under the amended
              revise to specify
       and2021
April 27,  restated
               Pageinvestors
                     4         rights agreement and the parties thereto.
FirstName LastName
 Daniel Jones
FirstName
SeqLL Inc.LastNameDaniel Jones
Comapany
April       NameSeqLL Inc.
       27, 2021
April 527, 2021 Page 5
Page
FirstName LastName
General

22.      Please supplementally provide us with copies of all written
communications, as defined in
         Rule 405 under the Securities Act, that you, or anyone authorized to
do so on your behalf,
         present to potential investors in reliance on Section 5(d) of the
Securities Act, whether or
         not they retain copies of the communications.
        We remind you that the company and its management are responsible for
the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action
or absence of
action by the staff.

       Refer to Rules 460 and 461 regarding requests for acceleration. Please
allow adequate
time for us to review any amendment prior to the requested effective date of
the registration
statement.

       You may contact Jenn Do at 202-551-3743 or Lynn Dicker at 202-551-3616
if you have
questions regarding comments on the financial statements and related matters.
Please contact
Margaret Schwartz at 202-551-7153 or Tim Buchmiller at 202-551-3635 with any
other
questions.



                                                               Sincerely,

                                                               Division of
Corporation Finance
                                                               Office of Life
Sciences
cc:      Eric M. Hellige, Esq.