X-ray microanalysis of the mid-gut epithelium of the fruitfly Drosophila melanogaster.

The cells in the mid-gut epithelium of Drosophila melanogaster which accumulate copper were examined by X-ray microanalysis. Both wavelength dispersive and energy dispersive analyses were used. The copper was located in granules o-3-1-o mum in diameter which were bounded by membranes and similar, morphologically, to secondary lysosomes. The copper was associated with high concentrations of sulphur but no other elements with an atomic number greater than 9 (the lower limit of the analysis equipment) were present in appreciable concentrations.