• The peptide calculator can be used to calculate molecular weights of peptides.  Sequences can be entered in upper case, lower case or mixed case.  The peptide calculator will convert all characters to upper case.
  • Select an N-terminal for your peptide.  If you select nothing the default is a free amine.
  • Select a linker.  This is optional.  If you select nothing the default is no linker.
  • Enter your peptide sequence in the text area by using the keyboard or pasting your sequence.  eg.  'A' for Alanine and 'C' for Cysteine. 
  • Enter 'J' for phoshhoSerine, 'U' for phosphoThreonine and 'O' for phosphoTyrosine and 'Z 'for Norleucine.
  • Enter 'X' for (S)-2(4'-pentenyl)Alanine.  Your sequence must contain two X's.
  • Select a C-terminal for your peptide.  If you select nothing the default is carboxylic acid.
  • The default molecular weight is average.  Use the option button for monoisotopic weights.
  • The default molecular weight is for linear peptides. 
  • Use the 'lactam' option buttons for lactam bridged peptides.  Lactam bridged peptides must contain at least one 'D' (or 'E') and one 'K' in the sequence.
  • Use the 'cyclic' option button for head to tail cyclic peptides.  Cyclic peptides must have 'acid' as the C-terminus and 'amine' as the N-terminus.
  • Use the 'stapled' option button for hydrocarbon stapled peptides.  Your sequence should contain only two X's [(S)-2(4-pentenyl)Alanine] for hydrocarbon stapled peptides.
  • The PNA calculator can be used to calculate the molecular weights of peptide nucleic acids (PNA).
  • PNA sequences can be entered in upper case, lower case or a mixture of cases.  Sequences can also be pasted.  The PNA calculator will convert all characters to lower case.
  • Valid PNA characters are 'a', 't', 'g' and 'c'.  Any other character will give an error.
  • The default N-terminus for PNA is free amine.  Select the 'O' linker for the commonly used aminooctanoic acid linker.
  • The default C-terminus for PNA is amide.  Select 'Lysine' or 'Lysine-Amide' if you need these instead.