Patent ID: 8691768

Claim:
A method of determining a delta opioid receptor subtype specificity of a composition, comprising: a) obtaining a neuronal cell preparation which comprises a cell, the cell naturally expressing at least one delta opioid receptor; b) exposing said preparation to a first agonist, known to selectively bind to a delta opioid subtype-1 receptor, wherein detecting a first neuronal response indicates binding of the first agonist to a delta opioid subtype-1 receptor; c) exposing said preparation to a second agonist, known to selectively bind to a delta opioid subtype-2 receptor, wherein detecting a first neuronal response indicates binding of the second agonist to a delta opioid subtype-2 receptor; d) wherein when a first neuronal response is detected and a second neuronal response is not detected, exposing a candidate composition to the cell preparation, wherein detecting a third neuronal response indicates the candidate composition is specific for delta opioid subtype-1; and e) wherein when a first neuronal response is not detected and a second neuronal response is detected, exposing a candidate agent to the cell preparation, wherein detecting a third neuronal response indicates the candidate composition is specific for delta opioid subtype-2.