Me 3In has been synthesised in a hydrocarbon solvent and has then been adduct purified using the nitrogen donor ligand 4,4′-methylenebis-(N,N′-dimethylaniline) (MBDA). The exclusion of ether from the synthesis and purification route leads to an ultra-low oxygen grade of Me 3In which allows the growth of InAlGaAs GRINSCH laser structures with high PL intensity. The crystal structures of the Me 3In[MBDA] 2 and (Me 3In) 2[MBDA] adducts are reported for the first time.