The present invention relates to a method for non-destructively identifying a characteristic of a
Gallus Gallus domesticus embryo in ovo, the method comprising: (a) obtaining a sample of material associated with an egg comprising the
embryo, and (b) measuring a
score value for the presence of, and concentration of at least a first biomarker in the sample indicative of the characteristic of the
embryo, and (c) applying a threshold to the
score value and concentration obtained in (b) to identify the characteristic for the embryo associated with the presence and concentration of the biomarker, wherein an at least first biomarker comprises an amino compound having a molecular weight in the range of from 140 to 190 g / mole, wherein step (c) further comprises: (i) correlating each relevant biomarker
signal with a reference biomarker by matching the spectrum of each correlating
signal with the expected spectrum of the correlating reference biomarker using a
similarity measure, to define at least one positively correlating
signal; (ii) measuring the intensity of each positively correlating signal and scoring its absolute and / or relative
signal intensity; and (iii) applying a threshold to the
score value obtained from a similarity function to determine the correlated embryo characteristic.