Analytical scanning electron microscopy and x-ray microdiffractometry of renal calculi using etched plastic sections

We describe the technique and illustrate results of renal calculi analyses utilizing correlative analytical scanning electron microscopy and x-ray microdiffractometry on the same 100 micrometer Spurr embedded sections. Essential to the technique is the employment of an extremely sensitive x-ray microdiffractometer, and for morphological analysis, pretreatment of the sections with a sodium ethoxide etching solution. This technique facilitates more precise identification of crystalline constituents especially calcium apatite and magnesium ammonium phosphate hexahydrate (struvite). Further, the technique permits detection and mapping of both crystalline and amorphous constituents within calculi.