Fig. 3From: MALDI-MSI: a fast and reliable method for direct melatonin quantification in biological fluidsQuantification of melatonin in light- and dark-period milk samples (n = 10/group) by MALDI-MSI. Unpaired T test as statistical test was employed (p < 0.05). Above each bar, there are examples of the images used for quantification of melatonin on respective samplesBack to article page