This is a non-competitive, firm-fixed-price contract intended to be awarded to Sigma-Aldrich for the purchase of 1 gram of L-Glutamic Acid (2,4 ¹³C2-99%), a specially labeled chemical required for NIH’s in vivo carbon-13 MR spectroscopy research on brain metabolism. The chemical is essential because natural ¹³C abundance is too weak for detection, and without it the institute would lose a powerful neuroscience research capability. The delivery location is NIH, NIMH, 10 Center Drive, Bldg. 10, Bethesda, MD 20892. The requirement is not set aside for small business, and the government plans to negotiate only with Sigma-Aldrich, though interested parties may submit capability information and pricing for consideration.