Fig. 3.

Synthesis of [³²P]NAADP. (A) HPLC traces of the test reactions using unlabeled compounds. First, NAD is converted to NADP using NAD kinase. Second, NADP is converted to NAADP using ADP-ribosyl cyclase. (B) Separation of the [³²P]NAADP from the reaction mixture. Detection of unlabeled compounds is performed by UV detection at 254 nm. ³²P-labeled compounds are detected as counts per minute (cpm) using an in-line Geiger counter.