Single crystal X-ray diffraction is the preferred method for structure determination of small molecules as well as protein and larger biological macromolecules. The complexity of samples that can be studied using X-ray techniques has improved significantly over recent years. Samples that were previously too small to be considered for single crystal X-ray analysis are now fully amenable to study. Highly unstable and weakly diffracting samples may be studied immediately, samples do not need to be discarded or undergo further recrystallization attempts.