Dear,

For the identification results, when amino acid C appears, whether the modification 
appears or not is random. In fact, pFind considers all possibilities of whether the 
modification occurs, and all possible outcomes are involved in the identification.
Therefore, this modification is considered for all amino acids C, but the end result is 
likely to be that only part of C is modified.

Best,
Wang kaifei

Maybe I forgot to send the picture, so my question may be misunderstood. I think 
the protein in pBuild may not display all carbamidomethyl[C]. So I don't know 
whether every C is considered.

Dear,

At present, the definitions of variable modification and fixed modification of pFind 
are very similar. Fixed modification should also consider all permutations and 
combinations of the modification. The only difference is that the max number of 
variable modifications per peptide is 3, but fixed modifications don't have this 
limitation.

Best,
Wang kaifei

In pFind, when I add modification of Carbamidomethyl[C], however in pBuild I find 
that the protein was modified in only one place.