MPEP § 2421.01 — Definition of “Sequence Listing” and Computer Readable Form (CRF) (Annotated Rules)

§2421.01 Definition of “Sequence Listing” and Computer Readable Form (CRF)

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 2421.01, including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Definition of “Sequence Listing” and Computer Readable Form (CRF)

This section addresses Definition of “Sequence Listing” and Computer Readable Form (CRF). Primary authority: 37 CFR 1.821(e), 37 CFR 1.822, and 37 CFR 1.824. Contains: 1 permission and 3 other statements.

Key Rules

Topic

Sequence Listing Content

7 rules
StatutoryInformativeAlways
[mpep-2421-01-fd1a2fc3e98abc6c2ef3daf1]
Requirement for Sequence Listing Content
Note:
The rule specifies the content requirements for sequence listings in applications filed before July 1, 2022.

[Editor Note: This section is not applicable to applications filed on or after July 1, 2022, having disclosures of nucleotide and/or amino acid sequences as defined in 37 CFR 1.831(b). See MPEP §§ 2412 – 2419 for applications filed on or after July 1, 2022.]

37 CFR 1.77 · 37 CFR 1.831(b)Sequence Listing ContentSequence Listing RequirementsSequence Listing Format
StatutoryInformativeAlways
[mpep-2421-01-0243d382f192d018a427dfdf]
Standard Format for Nucleic Acid and Amino Acid Sequences
Note:
Patent applications disclosing nucleic acid or amino acid sequences must use standard symbols and a standardized format for sequence data submission.

The sequence rules (37 CFR 1.821 – 1.825) require the use of standard symbols and a standard format for submitting sequence data in most patent applications that disclose nucleic acid or amino acid sequences. For purposes of the sequence rules and the discussion in MPEP Chapter 2400, the phrase “disclose(d) (or disclosure(s) of) nucleic acid or amino acid sequences” is intended to refer to those nucleic acid or amino acid sequences that are described in the patent application by enumeration of their residues and that meet the length thresholds of 37 CFR 1.821(a).

Jump to MPEP Source · 37 CFR 1.821Sequence Listing ContentSequence Listing FormatSequence Listing Requirements
StatutoryInformativeAlways
[mpep-2421-01-aff998e997835937ea269be5]
Disclosure of Nucleic Acid or Amino Acid Sequences Required
Note:
Patent applications must describe nucleic acid or amino acid sequences by enumerating their residues and meeting length thresholds.

The sequence rules (37 CFR 1.821 – 1.825) require the use of standard symbols and a standard format for submitting sequence data in most patent applications that disclose nucleic acid or amino acid sequences. For purposes of the sequence rules and the discussion in MPEP Chapter 2400, the phrase “disclose(d) (or disclosure(s) of) nucleic acid or amino acid sequences” is intended to refer to those nucleic acid or amino acid sequences that are described in the patent application by enumeration of their residues and that meet the length thresholds of 37 CFR 1.821(a).

Jump to MPEP Source · 37 CFR 1.821Sequence Listing ContentSequence Listing FormatSequence Listing Requirements
StatutoryInformativeAlways
[mpep-2421-01-72aaa25ab419d055923f1c48]
Sequence Listing Requirement for Nucleotide and Amino Acid Disclosures
Note:
Applications disclosing nucleotide and amino acid sequences must include a separate Sequence Listing in the format specified by 37 CFR 1.822 and 37 CFR 1.823.

37 CFR 1.821(c) requires that applications containing disclosures of nucleotide and/or amino acid sequences that fall within the definitions of 37 CFR 1.821(a) contain, as a separate part, a disclosure of the nucleotide and/or amino acid sequences, and associated information, using the format and symbols that are set forth in 37 CFR 1.822 and 37 CFR 1.823. This separate part of the disclosure is referred to as the “Sequence Listing”. See MPEP § 2422.03 for additional information.

Jump to MPEP Source · 37 CFR 1.821(c)Sequence Listing ContentSequence Listing FormatSequence Listing Requirements
StatutoryInformativeAlways
[mpep-2421-01-c5e8c8fe7616f10c9e0641a5]
Computer Readable Form for Sequence Listing Required
Note:
The CRF must be an ASCII plain text file following the format and content of 37 CFR 1.822, submitted via read-only optical disc or electronic filing system.

37 CFR 1.821(e) requires a separate computer readable form (CRF) of the “Sequence Listing” under certain circumstances. The CRF is an ASCII plain text file of the sequence information relating to the disclosure of the nucleotide and/or amino acid sequences using the symbols, format, content and file requirements of 37 CFR 1.822. See 37 CFR 1.824. The CRF may be submitted on read-only optical disc or may be submitted as an ASCII plain text file via the Office patent electronic filing system, pursuant to 37 CFR 1.821. The requirements regarding the CRF are discussed in detail in MPEP § 2422.04.

Jump to MPEP Source · 37 CFR 1.821(e)Sequence Listing ContentSequence Listing FormatSequence Listing Requirements
StatutoryPermittedAlways
[mpep-2421-01-c2a55725977dca2aa5e9a489]
CRF Can Be Submitted On Optical Disc Or ASCII File
Note:
The computer readable form of the sequence listing can be submitted as an ASCII plain text file via the Office electronic filing system or on a read-only optical disc.

37 CFR 1.821(e) requires a separate computer readable form (CRF) of the “Sequence Listing” under certain circumstances. The CRF is an ASCII plain text file of the sequence information relating to the disclosure of the nucleotide and/or amino acid sequences using the symbols, format, content and file requirements of 37 CFR 1.822. See 37 CFR 1.824. The CRF may be submitted on read-only optical disc or may be submitted as an ASCII plain text file via the Office patent electronic filing system, pursuant to 37 CFR 1.821. The requirements regarding the CRF are discussed in detail in MPEP § 2422.04.

Jump to MPEP Source · 37 CFR 1.821(e)Sequence Listing ContentSequence Listing FormatSequence Listing Requirements
StatutoryInformativeAlways
[mpep-2421-01-f99ceef2f3d8b921880b21bb]
Requirement for Separate Computer Readable Form of Sequence Listing
Note:
The rule requires a separate ASCII plain text file of sequence information in the form specified by 37 CFR 1.822, which may be submitted on read-only optical disc or via the Office patent electronic filing system.

37 CFR 1.821(e) requires a separate computer readable form (CRF) of the “Sequence Listing” under certain circumstances. The CRF is an ASCII plain text file of the sequence information relating to the disclosure of the nucleotide and/or amino acid sequences using the symbols, format, content and file requirements of 37 CFR 1.822. See 37 CFR 1.824. The CRF may be submitted on read-only optical disc or may be submitted as an ASCII plain text file via the Office patent electronic filing system, pursuant to 37 CFR 1.821. The requirements regarding the CRF are discussed in detail in MPEP § 2422.04.

Jump to MPEP Source · 37 CFR 1.821(e)Sequence Listing ContentSequence Listing FormatSequence Listing Requirements
Topic

Sequence Listing Format

2 rules
StatutoryInformativeAlways
[mpep-2421-01-4877ebdd9fc4ac0a2fa4d48f]
Requirement for Sequence Listing Format
Note:
Applications containing nucleotide and amino acid sequences must include a separate part with the specified format.

37 CFR 1.821(c) requires that applications containing disclosures of nucleotide and/or amino acid sequences that fall within the definitions of 37 CFR 1.821(a) contain, as a separate part, a disclosure of the nucleotide and/or amino acid sequences, and associated information, using the format and symbols that are set forth in 37 CFR 1.822 and 37 CFR 1.823. This separate part of the disclosure is referred to as the “Sequence Listing”. See MPEP § 2422.03 for additional information.

Jump to MPEP Source · 37 CFR 1.821(c)Sequence Listing FormatSequence Listing RequirementsSequence Listing Content
StatutoryInformativeAlways
[mpep-2421-01-151cb8886a665dafd764df9f]
Separate Computer Readable Form Required for Sequence Listing
Note:
A separate ASCII plain text file of sequence information must be submitted under certain circumstances.

37 CFR 1.821(e) requires a separate computer readable form (CRF) of the “Sequence Listing” under certain circumstances. The CRF is an ASCII plain text file of the sequence information relating to the disclosure of the nucleotide and/or amino acid sequences using the symbols, format, content and file requirements of 37 CFR 1.822. See 37 CFR 1.824. The CRF may be submitted on read-only optical disc or may be submitted as an ASCII plain text file via the Office patent electronic filing system, pursuant to 37 CFR 1.821. The requirements regarding the CRF are discussed in detail in MPEP § 2422.04.

Jump to MPEP Source · 37 CFR 1.821(e)Sequence Listing FormatSequence Listing RequirementsSequence Listing Content

Citations

Primary topicCitation
Sequence Listing Content
Sequence Listing Format
37 CFR § 1.821
Sequence Listing Content
Sequence Listing Format
37 CFR § 1.821(a)
Sequence Listing Content
Sequence Listing Format
37 CFR § 1.821(c)
Sequence Listing Content
Sequence Listing Format
37 CFR § 1.821(e)
Sequence Listing Content
Sequence Listing Format
37 CFR § 1.822
Sequence Listing Content
Sequence Listing Format
37 CFR § 1.823
Sequence Listing Content
Sequence Listing Format
37 CFR § 1.824
Sequence Listing Content37 CFR § 1.831(b)
Sequence Listing ContentMPEP § 2412
Sequence Listing Content
Sequence Listing Format
MPEP § 2422.03
Sequence Listing Content
Sequence Listing Format
MPEP § 2422.04

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2025-12-31