Mail Stop 3030
                                                                  March 9, 2018

     Emily M. Leproust, Ph.D.
     President and Chief Executive Officer
     Twist Bioscience Corporation
     455 Mission Bay Boulevard South, Suite 545
     San Francisco, CA 94158

            Re:     Twist Bioscience Corporation
                    Draft Registration Statement on Form S-1
                    Submitted February 8, 2018
                    CIK No. 0001581280

     Dear Dr. Leproust:

            We have reviewed your draft 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 providing the requested
information and either submitting
     an amended draft registration statement or publicly filing your
registration statement on
     EDGAR. 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 the information you provide in response to these
comments and your
     amended draft registration statement or filed registration statement, we
may have additional
     comments.

     Overview, page 1

     1.     We note the disclosure regarding customers in the last paragraph.
Please expand to
            disclose the amount of revenue attributable to the nine of the top
20 pharmaceutical
            companies, four of the largest agricultural biotechnology companies
and the "innovative
            customers" referenced on page 2.

     2.     We note the disclosure on page 106 that your products are marketed
and labeled as for
            "Research Use Only" and how this label limits their use. Please
disclose this limitation
            here and the impact on how your products may be marketed and sold.
Also revise to
            clarify how this limitation is reflected in the market data you
present in this submission,
            such as the $1.8 billion synthetic DNA market referenced on page 2
and the $4.0 billion
            synthetic biology products market referenced on page 1.
 Emily M. Leproust, Ph.D.
Twist Bioscience Corporation
March 9, 2018
Page 2

Implications of the Being an Emerging Growth Company, page 10

3.     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 communication.

Our revenue, results of operations, cash flows and reputation . . ., page 27

4.     We note the disclosure regarding the acquisition of a competing DNA
synthesis
       manufacturer by your largest customer and the possibility that it may
reduce purchases
       from you. Please revise to clarify how this relates to your largest
customer's obligations
       under the long-term contract mentioned on page 81. For example, can your
customer
       terminate the contract with no penalty? Also, if your largest customer
has informed you
       it will reduce or has actually reduced purchases from you or started
manufacturing
       synthetic DNA internally, please revise to disclose that information.

Use of proceeds, page 55

5.     Please quantify the amounts you intend to devote to each use referenced
in the third
       paragraph. Please also revise to clarify the uses referenced in (1), (3)
and (4) and what
       the amounts you intend to devote to that use will accomplish For
example, what
       improvements and updates do you intend to make? Into what geographies do
you intend
       to expand? What do you mean by the disclosure regarding "expand into new
business
       verticals?" Will you require additional funds to achieve the desired
goals?

Dilution, page 59

6.     Please expand the table on page 60 to disclose how the numbers and
percentages would
       change assuming the exercise of all outstanding options and warrants.

Value of orders received, page 66

7.     We note the disclosure that the value of orders received has increased
by seven times
       over the period you mention. Please revise to clarify the amount of
sequential growth for
       each quarter during that period.

8.     Please revise to disclose the value of orders received from Ginkgo
Bioworks.

Number of customers, page 66

9.     Please clarify what you mean by the terms "separate person or legal
entity" and "separate
       legal entity," as disclosed here and on page 67, as those terms relate
to your customers.
       For example, would purchases by two subsidiaries of the same parent
company qualify as
 Emily M. Leproust, Ph.D.
Twist Bioscience Corporation
March 9, 2018
Page 3

       purchases by two customers? If so, please revise to clarify how the data
you present
       would change if such purchases were considered to be made by only one
customer.

Results of operations, page 69

10.    Please revise to clarify and quantify the effect of changes in price,
volume and new
       products on the results you disclose, and the reasons underlying those
changes, and how
       the 2017 agreement with Ginkgo Bioworks impacted your results. Please
also revise to
       quantify the changes in revenues of each of the products to which you
refer. In this
       regard, please revise to disclose the information required by Regulation
S-K Item
       101(c)(1)(i).

Research and development expenses, page 70

11.    We note the quantitative disclosure regarding changes to the components
of research and
       development expenses. Please revise to explain the reasons for those
changes. Please
       also provide similar disclosure regarding the components of selling,
general and
       administrative expenses.

Debt Financings, page 72

12.    Please revise to clarify your ability to access amounts available under
the second and
       third advances of your loan and security agreement, including any
material conditions
       you have to satisfy.

Critical accounting policies and estimates

Stock-based compensation, page 77

13.    Please revise your filing to explain in more detail the methodologies
and material
       assumptions that your board of directors utilized in determining the
fair value of your
       common stock underlying your equity instruments granted during the
periods presented.

14.    Additionally, provide us with the share price of your common stock
determined by your
       board of director's at the date of each option grant since January 1,
2017 and
       progressively bridge for us the fair value per share determinations used
for each option
       grant to the estimated IPO price per share. We will delay our assessment
of your
       response pending inclusion of the estimated IPO price in the filing.

Overview, page 80

15.    Please revise to clarify each party's obligations under Ginkgo Bioworks'
2017 agreement
       with you. For example, clarify how the amount of base pairs is allocated
over each year
 Emily M. Leproust, Ph.D.
Twist Bioscience Corporation
March 9, 2018
Page 4

       of the three-year period and the purchase price. Also clarify any
material termination
       rights held by each party.

Suppliers, page 101

16.    Please revise to clarify the nature of your arrangements with the
suppliers of the two
       critical components mentioned here. For example, do you obtain materials
on a purchase
       order basis at a fixed price? Are you guaranteed a minimum amount each
year? What is
       the duration of each agreement? Also, given your disclosure on page 25
regarding the
       material risks related to these agreements, please file these agreements
as exhibits.

17.    Please clarify what you mean by "substantial stockpile," as disclosed on
page 25. Also
       revise to clarify the impact on you if you had to rely on alternative
suppliers. For
       example, describe the duration and extent to which your manufacturing
process would be
       interrupted, given your disclosure that such process was designed based
on the materials
       provided by these suppliers.

Legal proceedings, page 104

18.    Please revise to clarify the factual basis alleged to underlie the
proceeding referenced
       here and the relief sought.

Principal stockholders, page 137

19.    Please identify the natural persons who have or share voting and/or
dispositive powers
       over the shares held by Tao Invest and Paladin Capital Group.

Directed shares, page 155

20.    From your disclosure here, it appears that shares purchased by your
directors and officers
       in the directed share program will be subject to a lock-up restriction,
but shares purchased
       by "certain employees and other parties related to [you]" will not be
subject to that
       restriction. If that is correct, please revise for clarity. Ensure your
revisions are
       consistent with the disclosure on page 152 that "all of our
stockholders" have entered into
       lock-up agreements.

Note 2. Summary of significant accounting policies

Accounts Receivable, page F-10

21.    Please revise your filing to disclose the allowance for doubtful
accounts for each
       reporting period presented as required by ASC 310-10-50-4.
 Emily M. Leproust, Ph.D.
Twist Bioscience Corporation
March 9, 2018
Page 5

Revenue Recognition, page F-12

22.    We note disclosure of the combination of technology related to the
manufacturing of
       synthetic DNA with proprietary software to create an integrated
platform. Please
       describe the promises to transfer goods or services in your customer
contracts and how
       you considered those promises in determining your performance
obligations. Include
       how you evaluate whether the technology and software represent separate
promises.

23.    On page 66, you disclose the value of orders received. Please also
disclose the aggregate
       amount of transaction price allocated to unsatisfied purchase orders.
Refer to ASC 606-
       10-50-13.

24.    We note from page F-14 that you receive payments from DARPA pursuant to
a research
       and development agreement. Please tell us how you determined that the
agreement
       should not be included within the scope of ASC 606.

Note 17. Geographic Information, page F-38

25.    We note your disclosure on page 91 that you offer four different
products comprised of
       synthetic genes, oligo pools, next generation sequencing tools and DNA
libraries. Please
       tell us how you considered the product line disclosure required by ASC
280-10-50-40.

        You may contact Tara Harkins at (202) 551-3639 or Kevin Kuhar,
Accounting Branch
Chief, at (202) 551-3662 if you have questions regarding comments on the
financial statements
and related matters. Please contact Geoff Kruczek at (202) 551-3641 or me at
(202) 551-3528
with any other questions.


                                                           Sincerely,

                                                           /s/ Amanda Ravitz

                                                           Amanda Ravitz
                                                           Assistant Director
                                                           Office of
Electronics and Machinery


cc:    John V. Bautista, Esq.
       Christopher J. Austin, Esq.
       Peter M. Lamb, Esq.