Dopamine Receptor Binding and Quantitative Autoradiographic Study - Drugs of Abuse: Neurological Reviews and Protocols - page 298

Fig. 2. Representative data from a 10-point saturation radioligand binding exper-
iment ( see Ta b l e 1 ). Data shown are for [ 3 H]PD 128907 binding in rat ventral
striatal membranes. Saturation data, expressed in dpm, is shown in (A) . A Rosenthal
(Scatchard) plot of the same data is shown in (B) . Results of this experiment, as
analyzed by LIGAND, were K D = 0.21 n M , B max = 23 fmol/mg of protein.
Data can then be analyzed using any of a variety of computer programs
for analysis of radioligand binding data such as LIGAND, EBDA, etc. Alter-
natively, data may be transformed an analyzed manually.
For manual analysis, determine the amount of specifi c binding at each
concentration ( see Note 14 ):
Specifi c binding = total binding - nonspecifi c binding
Binding data at each concentration of radioligand can then be plotted to
generate a saturation curve ( Fig. 2A ).
Data are then transformed and plotted in a Rosenthal (Scatchard) plot
(Fig. 2B) . First, convert specifi c binding counts into moles bound using the
following equation: