The potential value of carcass chemical analysis in a variety of animal research studies is not only in the specific information it alone can provide, but in particular as a means of substantiating and augmenting data obtained from other experimental approaches. For example, it may be used in conjunction with in vivo nutrient balance studies and with physical dissection in carcass quality assessment studies. Realization of the full potential value of carcass chemical analysis depends entirely, however, on the ability to produce, from the initial highly heterogeneous carcass material, a fully representative sample that is sufficiently homogeneous to enable valid analyses to be made using the desired analytical techniques. Macro-analytical techniques may be acceptable when the numbers of samples involved are relatively small and /or when the analytical resources available are not critical. Under such conditions a lower degree of homogeneity will be acceptable in the material to be analysed than that required when micro-analytical techniques are used.