The examination of the mass-spectra showed an absence of the oxidized form of peptide LC 10-28, thus we determined only the contents of oxidized peptides HC 150-156 and HC 118-140.
I'm not sure about the use of articles here. Does the "where is room 301" rule apply here?
"LC 10-28" is a kind of code indicating the position of the peptide in the light chain of the antibody molecule. Looks like the number "301" in "room 301".
Or does it work like a proper name here, necessitating the use of the definite article?
The examination of the mass-spectra showed an absence of the oxidized form of the peptide LC 10-28, thus we determined only the contents of oxidized peptides HC 150-156 and HC 118-140.
A peptide is not exactly like a "room", this is one thing that confuses me. Peptides differ in their length and amino acid composition.