Abstract: Method and apparatus for analysing a fractionated liquid sample received in a vessel having a reference feature, the method comprising capturing an image of the reference feature and an image of a first boundary of a first fraction within the sample, and analysing the captured images to determine the separation of the first boundary from the reference feature. The determined separation can then be used to calculate, for example, the volume of the first fraction associated with the first boundary. Methods and apparatus for aspirating desired volumes from analysed samples are also described.