The Death Ray and the Lab Coat were both part of a replica costume of Dr. Horrible from the movie Dr. Horrible's Sing-Along Blog.
I made this coat from scratch, starting from about five yards of fabric. I modified McCall's pattern 2233, cut the pieces, and sewed all the seams and buttonholes. The only thing I didn't do myself was the embroidery, which my grandmother was kind enough to do.
Wearing the costume, complete with goggles, gloves and boots.
The lab coat worn by Neal Patrick Harris in the film.