The purified products were >95% radiochemically
pure based on the size exclusion HPLC profiles.
The p-MAO-B activity was determined radiochemically
in duplicate samples as described by Coccini et al.
MAO activity was radiochemically
assayed as previously described  using [[sup.14]C]- 5-HT (1.0 [micro]Ci/mL; 100 [micro]M; Amersham Biosciences, UK) or [[sup.14]C]-benzylamine (1.0 [micro]Ci/mL; 100 [micro]M; Amersham Biosciences, UK) as substrates for MAO-A and B, respectively.
Following preconcentration and matrix simplification [via metal oxide/hydroxide co-precipitation; i.e., Fe[(OH).sub.3] and Mn[O.sub.2]], Po, U, and Th were separated into radiochemically
pure fractions via extraction chromatography.
A simple three-step synthesis was used to prepare radiochemically
pure [[sup.18]F]FLT--98% [+ or -] 0.98%, at the end of synthesis within 45 min and with a 15% [+ or -] 7.6% radiochemical yield.
Total and free carnitine were radiochemically
assayed directly in either serum or skeletal muscle homogenates with a modified method of Barth et al.