To demonstrate the effectiveness of the probe on biological samples, it was used to distinguish between different types of healthy brain tissue. Spectra were acquired from porcine brain tissue (obtained from pigs destined for human consumption). One hundred and twenty spectra were acquired of white matter, gray matter, and blood vessels (identified by eye) from a pig brain. A laser excitation of 20 mW at the sample was used, and an acquisition time of 60 s. Laser power was restricted to 20 mW due to limitations in available equipement. These spectra are shown with background subtraction applied in Fig. 5, and without subtraction in Fig. 6. The sample fluorescence has been removed from these spectra using a gradient domain approach (outlined in Zhao et al.31) for clarity. These spectra exhibit the expected Raman bands from brain tissue, previously reported in the literature,23 with cholesterol (430, 705, ), fatty acid (1130, 1298, ), ceramide (), and sphingomyelin () Raman peaks all visible. It is also immediately apparent that there are discriminatory differences below , a region where the silica background of the needle probe is very prevalent, and hence this spectral information would typically be discarded.