A device and method which enable a transmission electron microscope to measure electron diffraction patterns of a sample very precisely are disclosed. Specifically, the present invention consists of an emulsion blend comprising an aqueous emulsion of polydimethylsiloxane and an aqueous emulsion of organopolysiloxane which upon drying forms a solid elastomeric film of siloxane; and a polyol. A further subject of the invention is -1–2-amino-3–8–2-phenyl-5,6-dihydroimidazo1,2-apyrazin-7-yl-3-oxopropyl}dithio)methyl-2–8–2-phenyl-5,6-dihydroimidazo1,2-apyrazin-7-yl-2-oxoethylamine, or a pharmaceutically acceptable salt thereof, useful as an anticancer agent.