Sequence analysis
Peptide Molecular Weight Calculator
Calculate theoretical neutral monoisotopic mass, common protonated m/z values, sequence length and amino-acid composition from a one-letter peptide sequence.
Open Calculator Free research utilities
Laboratory tools designed to make analytical research work easier to review.
Practical, shareable utilities for peptide sequence notation, molecular calculations, and analytical-documentation review, with clear assumptions and research-use-only boundaries.
Sequence notation
Amino Acid Sequence Converter
Convert peptide sequences between standard one-letter and three-letter amino-acid notation, review residue names, and copy formatted output for laboratory documentation.
Open ConverterDocumentation review
Peptide COA Review Checklist
Review whether a Certificate of Analysis contains core lot identifiers, dates, analytical evidence and traceability fields. The score measures documentation completeness only.
Open ChecklistAnalytical context
Calculations and checklists are most useful when connected to the underlying analytical method.
Molecular-weight calculations describe a theoretical sequence-derived value. HPLC, mass spectrometry and COA review answer different questions about a physical sample or lot. Use the supporting guides below to interpret each result within the correct laboratory context.