Digest Mass Filter

Filter digest peptides by calculated monoisotopic neutral mass.

Description

Digest mass filtering retains supplied peptides whose calculated neutral masses lie within a chosen interval.

Digest mass filtering retains supplied peptides whose calculated neutral masses lie within a chosen interval. Filtering does not simulate digestion itself.^[1]

Filter digest peptides by calculated monoisotopic neutral mass.

When to use Digest Mass Filter

Use this tool to filter digest peptides by calculated monoisotopic neutral mass.

Prepare the canonical sequence, peptide assignments, fitted assay parameters or upstream measurements requested. Keep corresponding entries aligned, use the stated mass and signal units, and remove FASTA headers before entering sequence text.

How to use Digest Mass Filter and understand its results

Prepare the canonical sequence, peptide assignments, fitted assay parameters or upstream measurements requested. Keep corresponding entries aligned, use the stated mass and signal units, and remove FASTA headers before entering sequence text.
Enter peptideSequences, minimumMassDa, maximumMassDa using the field table and calculation rules, then run the tool.
Read retainedSequences, peptideMassesDa. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
peptideSequences	Peptide sequences	list of string	Required
minimumMassDa	Minimum mass da	number	Required
maximumMassDa	Maximum mass da	number	Required

Enter peptide strings and ordered nonnegative mass bounds. Validate each as canonical sequence, calculate residue-sum mass plus 18.01056 Da water, and return retained original strings and masses for every input in order. Empty lists are allowed.

The shared sequence helper trims outer whitespace and uppercases the sequence. It requires at least one residue from ACDEFGHIKLMNPQRSTVWY. Internal whitespace, FASTA headers, ambiguous letters and modified-residue notation are rejected. Sequence indexes refer to the normalized sequence; individual tools may preserve original strings in their returned lists as explained above.

retain peptide_i if minimum≤monoisotopicMass_i≤maximum

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
retainedSequences	Retained sequences	list of string
peptideMassesDa	Peptide masses da	list of number

json

{
  "input": {
    "peptideSequences": [
      "A",
      "GG",
      "WW"
    ],
    "minimumMassDa": 70,
    "maximumMassDa": 200
  },
  "output": {
    "retainedSequences": [
      "A",
      "GG"
    ],
    "peptideMassesDa": [
      89.04767,
      132.05348,
      390.16918
    ]
  }
}

Limitations and assumptions

Masses are returned for all peptides, not only retained ones. Original case/outer whitespace is preserved in retained strings; modifications are not supported.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Digest Length Filter: Filter peptide sequences by caller-selected residue length range. For a complementary task, use Peptide Neutral Mass: Calculate monoisotopic neutral peptide mass from its canonical sequence.

References

Digest Mass Filter — tool.io

Similar or alternative tools

Digest Length Filter
Filter peptide sequences by caller-selected residue length range.
Peptide Neutral Mass
Calculate monoisotopic neutral peptide mass from its canonical sequence.