Patentable Subject Matter (35 USC 101; MPEP 2100)

by patentbar on November 21, 2007 · 24 comments

in 35 USC 101, MPEP 2100

MPEP Chapter 2100 covers the fundamental issues of patentability – what is patentable subject matter and how that matter must be expressed in an applicant’s disclosure. The Prometric Patent Bar tests MPEP 2100 heavily.

Note: MPEP 2100 also includes 35 USC 102 (a)-(g), 35 USC 103 and 35 USC 112, which are discussed in other posts under MyPatentBar’s Study Guide, PART 2.

What is patentable subject matter? Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefore, subject to the conditions and requirements of this title.” [35 USC 101]

To be patentable an invention must fall into one of the following statutory categories:
1) machine – e.g., new gizmo
2) manufacture (combination of materials) – e.g., new widget (gardening tool, computer chip)
3) composition of matter – e.g., new chemical composition or metal alloy
4) process (a new method for doing something) – note: special sub-category product by process

A claim cannot cite more than one of the statutory categories above (i.e., it is inappropriate to refer to a machine and composition of matter in the same claim).


  • Product: a new, useful and non-obvious machine, manufacture, or composition of matter (see statutory categories 1-3 above).
  • Process: a new, useful and non-obvious way of doing something, making something, or using something. A process may be patentable even though the resulting product itself is not.  Also, a process claim must include steps; it cannot claim the result without any steps (see comment below).
  • Product-by Process: patentability is based on the product, not the process. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious over a product in the prior art, the claim is unpatentable even though the prior product was made by a different process.
    • Living subject matter is patentable: human intervention is necessary (e.g., genetically engineered material)
    • Also patentable are claims directed to a practical application of a natural phenomenon

    Not Patentable – examples

    • Naturally occurring living subject matter or raw materials
    • Inventions for which the broadest reasonable interpretation encompasses a human being
    • Mathematical, physical and natural laws
    • Processes that depend on natural laws, abstract ideas, etc. without some claimed practical application
    • Computer-related, descriptive material; this is copyrightable

    How that matter must be expressed in an applicant’s disclosure; Claim Interpretation

    • During examination, claims must be “given their broadest reasonable interpretation consistent with the specification.”
    • The words of the claim must be given their “plain meaning” unless they are defined in the specification.
    • The transitional phrases “comprising,” consisting essentially of,” and “consisting of” define the scope of a claim with respect to what unrecited additional components if steps, if any, are excluded from the scope of the claim. [MPEP 2111.03]
      • Comprising – non-exclusive language
      • Consisting essentially of – limiting language*
      • Consisting of – exclusive language*

      *revised from dk’s comment below

    { 24 comments… read them below or add one }

    1 patentbarNo Gravatar November 28, 2007 at 12:41 am

    examiner has burden to prove unpatentability by preponderance of evidence (51%)


    2 dkNo Gravatar February 13, 2008 at 9:25 pm

    I first want to thank you for setting this website. It is a invaluable tool for me to prepare for the patent bar.

    I think your last bullets about transitional phrases have a misinformation. I think it should be

    * Comprising – non-exclusive language
    * Consisting essentially of – limiting language
    * Consisting of – exclusive language

    because MPEP 2111.03 states that:
    “A ‘consisting essentially of’ claim occu­pies a middle ground between closed claims that are written in a ‘consisting of’ format and fully open claims that are drafted in a ‘comprising’ format.”


    3 patentbarNo Gravatar February 21, 2008 at 11:48 pm

    A product-by process is a claim that encompasses the product produced by claim #1. It is the product and not the process that determines patentability. You already have a claim directed toward the process (claim #1). For example, in the same application – you have claim #1 (the process) and claim #2 (the product-by process).


    4 patentbarNo Gravatar February 22, 2008 at 12:01 am

    A proper process claim must include the actual steps. (For example, a process of “doing something” comprising of … and lists a series of steps). “The use of a water replant paint to water-proof patio furniture” – does not recite specific acts for how that process is accomplished, and is not a proper process claim. YOU MUST CITE the steps involved to achieve a result, just citing the result is not sufficient.


    5 patentbarNo Gravatar February 22, 2008 at 12:11 am

    To satisfy the utility requirement (part 2 of USC 101), you must only state a benefit. When there is a lack of utility, you will usually also have a lack of enablement (USC 112 p1). This means that a rejection based on utility will accompany a rejection based on enablement.


    6 JBagNo Gravatar September 18, 2009 at 5:27 pm

    One way I remember the differences between consisting and comprising is that “consisting is consistant where comprising can compromise.”


    7 DanTNo Gravatar August 4, 2011 at 12:56 pm

    Does anyone have experience using the OmniPrep patent bar prep course?

    I am a recent law school graduate looking to start preparing for the patent bar, and I was curious if anyone had any recommendations related to professional preparation courses.

    OmniPrep is by far the most reasonably priced I have found, but if I am going to invest the time I want to make certain I am putting myself in a position to pass.

    Any insight would be greatly appreciated.


    8 BobNo Gravatar August 4, 2011 at 6:21 pm

    I don’t know much about OmniPrep, but I’ve heard it’s not the best. You can find a used PLI course on eBay for the same or even less. That’s what I used to pass and it was great.


    9 BobNo Gravatar August 4, 2011 at 6:31 pm

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    10 DavidNo Gravatar August 4, 2011 at 9:42 pm

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    11 SundayNo Gravatar August 29, 2011 at 11:40 am

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    12 DanTNo Gravatar August 5, 2011 at 3:35 pm


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    18 patentNo Gravatar March 29, 2014 at 10:35 am

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    21 DaniyalNo Gravatar April 8, 2014 at 6:47 pm
    22 PaulinaNo Gravatar May 9, 2014 at 2:59 pm

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    23 himaNo Gravatar June 11, 2014 at 2:04 pm

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    24 Bfusion.No Gravatar June 11, 2014 at 5:53 pm

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