Detection of cannabis use
A binding partner, especially an antibody fragment that specifically recognizes an antigen-antibody immune complex between anti-THC and THC (tetrahydrocannabinol), is disclosed. The binding partner facilitates a non-competitive homogenous immunoassay for detection of cannabis use. A test kit comprising the binding partner is also described. Preferably the immunoassay is applied for roadside testing of saliva from suspected drivers.
1. An isolated binding partner comprising the complementary determining regions (CDRs) of an antibody light chain and heavy chain, wherein said light chain regions have the amino acid sequences of amino acids 23-35, 51-57, and 93-100 of SEQ ID NO:3, and said heavy chain regions have the amino acid sequences of amino acids 29-35, 50-60 and 99-109 of SEQ ID NO:4.
2. The binding partner according to claim 1 , which is an antibody fragment.
3. The binding partner according to claim 2 , wherein the antibody fragment comprises amino acids 1-111 of SEQ ID NO:3, and amino acids 1-120 of SEQ ID NO:4.
4. The binding partner according to claim 2 , wherein the antibody fragment is Fab 104 comprising SEQ ID NO:3 and SEQ ID NO:4.
5. The binding partner according to claim 1 , which specifically recognizes an immune complex between tetrahydrocannabinol (THC) and anti-THC.
6. A test-kit comprising the binding partner of claim 1 .
7. The test-kit according to claim 6 , further comprising another binding partner comprising the complementary determining regions (CDRs) of an antibody light chain and heavy chain, wherein said light chain regions have the amino acid sequences of amino acids 24-35, 51-57, and 90-98 of SEQ ID NO:1, and said heavy chain regions have the amino acid sequences of amino acids 27-36, 51-66 and 99-107 of SEQ ID NO:2.
8. The test kit according to claim 7 , wherein the two binding partners are labeled with fluorophores.
9. An isolated polynucleotide encoding the binding partner of claim 1 .
10. An isolated host cell that has been transformed with an isolated polynucleotide encoding the binding partner of claim 1 and being capable of expressing the binding partner of claim 1 .
11. A method for detecting cannabinoid in a body sample taken from a person to be tested for having used cannabis, comprising:
reacting the body sample with a reagent pair comprising a first binding partner that specifically binds to a cannabinoid in the body sample to form a complex and a second binding partner that specifically binds to the complex; and
determining the binding of the second binding partner to the complex thereby indicating presence of the cannabinoid in the body sample,
wherein said first binding partner comprises the complementary determining regions (CDRs) of an antibody light chain and heavy chain, wherein said light chain regions have the amino acid sequences of amino acids 24-35, 51-57, and 90-98 of SEQ ID NO:1, and said heavy chain regions have the amino acid sequences of amino acids 27-36, 51-66 and 99-107 of SEQ ID NO:2, and
said second binding partner is the binding partner according to claim 1 .
12. The method according to claim 11 , wherein the cannabinoid is THC.
13. An immunoassay for detecting a cannabinoid in a sample taken from a body, comprising:
reacting the sample with a reagent pair comprising a first binding partner that specifically binds to the cannabinoid to form a complex, and a second binding partner that specifically binds to the complex; and
determining the binding of the second binding partner to the complex, thereby indicating presence of the cannabinoid in the sample,
wherein said first binding partner comprises the complementary determining regions (CDRs) of an antibody light chain and heavy chain, wherein said light chain regions have the amino acid sequences of amino acids 24-35, 51-57, and 90-98 of SEQ ID NO:1, and said heavy chain regions have the amino acid sequences of amino acids 27-36, 51-66 and 99-107 of SEQ ID NO:2, and
said second binding partner comprises the complementary determining regions (CDRs) of an antibody light chain and heavy chain, said light chain regions having the amino acid sequences of amino acids 23-35, 51-57, and 93-100 of SEQ ID NO:3, and said heavy chain regions having the amino acid sequences of amino acids 29-35, 50-60 and 99-109 of SEQ ID NO:4.
14. The immunoassay of claim 13 , which is a non-competitive, homogenous immunoassay.
15. The immunoassay of claim 14 , wherein the non-competitive homogenous immunoassay is a time resolved fluorescent resonance energy transfer (TR-FRET) assay.
16. The immunoassay of claim 13 , wherein the sample to be analyzed is selected from the group consisting of blood, urine, and oral fluid.
17. The immunoassay of claim 13 , wherein the sample is saliva and the cannabinoid is tetrahydrocannabinol (THC).