Patent ID: 8916680

Claim:
A method for determining by mass spectrometry the amount in a sample of one or more kisspeptin-54-derived peptides selected from the group consisting of kisspeptin-54, kisspeptin-53, kisspeptin-52, kisspeptin-54(R14P), kisspeptin-53(R14P), and kisspeptin-52(R14P), said method comprising: (a) subjecting the sample to ionization under conditions suitable to produce one or more multiply charged kisspeptin-54-derived peptide ions detectable by mass spectrometry; (b) determining by mass spectrometry the amount of one or more multiply charged ions selected from the group of ions with a charge consisting of 4+, 5+, 6+, and 7+ from each of said one or more kisspeptin-54-derived peptides; and (c) using the amount of the determined ions to determine the amounts of the corresponding one or more kisspeptin-54-derived peptides in the sample.