Peptide Mass Error Dalton
Calculate peptide mass error in daltons.
Description
Mass error compares an observed mass with a theoretical reference in daltons.
Mass error compares an observed mass with a theoretical reference in daltons. Its sign indicates whether the observation is higher or lower.1
Calculate peptide mass error in daltons.
When to use Peptide Mass Error Dalton
Use this tool to calculate peptide mass error in daltons.
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 Peptide Mass Error Dalton 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 observedMassDa, theoreticalMassDa using the field table and calculation rules, then run the tool.
- Read signedErrorDa, absoluteErrorDa. 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 |
|---|---|---|---|
| observedMassDa | Observed mass da | number | Required |
| theoreticalMassDa | Theoretical mass da | number | Required |
Enter strictly positive masses on the same neutral-mass or m/z basis. Return signed and absolute differences.
signedErrorDa=observed−theoretical; absoluteErrorDa=|signedErrorDa| Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| signedErrorDa | Signed error da | number |
| absoluteErrorDa | Absolute error da | number |
{
"input": {
"observedMassDa": 501,
"theoreticalMassDa": 500
},
"output": {
"signedErrorDa": 1,
"absoluteErrorDa": 1
}
}Limitations and assumptions
The tool does not align peaks, determine charge or assess a tolerance. Mixing neutral mass with m/z produces an uninterpretable difference.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Fragment Tolerance PPM: Convert a fragment mass tolerance from daltons to ppm. For a complementary task, use Peptide Neutral Mass: Calculate monoisotopic neutral peptide mass from its canonical sequence.
References
-
Peptide Mass Error Dalton — tool.io
Similar or alternative tools
- Fragment Tolerance PPM
Convert a fragment mass tolerance from daltons to ppm.
- Peptide Neutral Mass
Calculate monoisotopic neutral peptide mass from its canonical sequence.