Table 2.

Sample conversion of total [³H]-(+)-pentazocine counts into nanomolar concentrations in assay

Targeted [3H]-(+)-PTZ concentration (nM)	Measured total radioactivity (DPM)	Measured total [3H]-(+)-PTZ (mmol)	Measured [3H]-(+)-PTZ concentration in assay (nM)
300	2037960	2.70E-08	270.0
100	679420	9.00E-09	90.0
30	204684	2.71E-09	27.1
10	66382	8.79E-10	8.8
3	21047	2.79E-10	2.8
1	6573	8.71E-11	0.9
0.3	2234	2.96E-11	0.3

The first column displays targeted concentrations of [³H]-(+)-pentazocine calculated from the stock vial (34 Ci/mmol or ~29.4 μM). Second column contains radioactivity counts in DPM of the targeted concentration of [³H]-(+)-pentazocine. Third column shows radioactivity values transformed from DPM into millimoles of radioligand (Note: the conversion factor used was 2.22 × 10¹² DPM per Ci). The fourth column shows the actual concentrations of [³H]-(+)-pentazocine as calculated from the DPM values obtained.