In This Issue:

  • New Vice President of Business Development, Graham Long, Ph.D. 
  • Aptamers and Opioid Drugs of Abuse
  • Base Pair Develops Aptamers that Selectively Bind to Noroxycodone and Norhydrocodone


Aptamers and Opioid Drugs of Abuse

Opiates and opioids are frequently prescribed to treat pain. These drug molecules bind to opioid receptors and block the transmission of pain signals within the central nervous system and gastrointestinal tract. [1] At the same time, they drive up levels of dopamine, a hormone producing an addictive feeling of euphoria. [2] Natural opiates (codeine, morphine) are directly derived from the opium poppy. Semi-synthetic opioids (heroin, hydrocodone), are chemically synthesized, but include natural opiate derivatives. Some opioids (methadone, fentanyl), are completely synthetic, but have a similar effect to that of natural opiates. [1] 100 times more potent than morphine and 30 to 50 times more powerful than heroin, prescription fentanyl is sometimes prescribed to cancer patients and is routinely used in anesthesia. [2]
According to a CNN article earlier this month, the CDC is reporting overdoses in the U.S. from illicit opioids rose dramatically in 2015. Overdose deaths from synthetic opioids were up 73% to 9,580. Most were related to illicit fentanyl. 17,536 deaths involved prescription opioids and 12,990 deaths were related to heroin. [2] In many cases, heroin is tainted with other drugs or additives used in production. Levamisole is a contaminant in about 69% of the cocaine used in the U.S. A recent publication describes the potential effects of levamisole, including kidney toxicity (nephrotoxicity), destruction of blood vessels (cutaneous vasculitis), and immune deficiency caused by severe reduction of neutrophil formation in bone marrow (agranulocytosis). [3] An excerpt from a June 24th Fox news story reads, “Officials in New Haven have declared a public health emergency following a string of overdoses linked to a batch of heroin mixed with fentanyl.” [4] Similar stories are being written throughout the U.S. 

According to a CNN news report and research letter published in JAMA Pediatrics on December 12, 2016, the incidence of neonatal abstinence syndrome (NAS), or opioid withdrawal in newborns, increased 5-fold in the U.S. from 2000 to 2012 [5,6] Recent increases in opioid deaths and NAS highlight the need for improved screening. Tests for detecting a wider range of opioids and common contaminants could assist law enforcement in the identification of “tainted” drugs, assist health care providers in identifying drug compounds or “cocktails” that were ingested or are present in newborns, and assist family members in diagnosing drug dependence. While there are several FDA-approved home use tests for drugs of abuse, including cocaine, methadone, morphine, and oxycodone, tests for many synthetic and semi-synthetic opioids are lacking. [7] In January 2014, law enforcement in some towns began administering naloxone, to reverse opioid effects in cases of overdose. [8] In March 2014, the FDA approved a hand-held device for administration of naloxone by family members. [9] Identifying opioid use can enable access to early treatment.
Developing specific reagents and tests for detecting opioids and opioid metabolites has proven difficult and time-consuming. While research abounds with antibodies to opioid receptors, antibodies to opioids themselves are few and far between.  Because opioids are small molecules, their immunogenicity is generally low and techniques for altering small molecules to induce antibody production often fail or negatively affect antibody specificity. [10,11,12] In recent years, researchers have been turning to aptamers, chemically-synthesized single strands of DNA or RNA that form unique secondary and tertiary structures to selectively bind a wide range of targets. [13] In 2006, researchers at the University of Illinois developed a simple test for cocaine in bodily fluids using aptamers. [14] Since then, similar tests for common drug compounds, such as methamphetamines, have been published. [15,16] In response to the growing use and abuse of a wider range of opioids, Base Pair has successfully developed a number of aptamers that selectively bind to opioids and opioid metabolites. Two of these molecules are described in the product highlights section below.

Base Pair Product Highlights
Base Pair Develops Aptamers that Selectively Bind to Noroxycodone and Norhydrocodone

​According to the U.S. Drug Enforcement Administration, hydrocodone and oxycodone have been the two most widely distributed controlled prescription drugs in the U.S. from 2006 to 2014. Since 2002, the number of deaths linked to prescription pain killers has exceeded the numbers due to cocaine and heroin combined. [17] Noroxycodone and norhydrocodone are unique metabolites of oxycodone and hydrocodone, respectively. [18] Oxycodone is N-demethylated to form noroxycodone by cytochrome P450 34A. It is O-demethylated by cytochrome P450 2D6 to form oxymorphone, an active metabolite. [19] Hydrocodone undergoes N-demethylation by cytochrome P450 3A4 to form norhydrocodone. It undergoes O-demethylation catalyzed by cytochrome P450 2D6 to form the active metabolite hydromorphone. [20] Presence of the noroxycodone and norhydrocodone metabolites have a high correlation to the parent drugs. Because these metabolites are not administered directly to drug users, their presence in the urine has a direct correlation to use of hydrocodone or oxycodone. {18,19,20] Metabolite detection in the urine of neonates indicates maternal use of hydrocodone or oxycodone during pregnancy.

​Base Pair performed an aptamer selection project for the National Institutes of Health using a urine-like synthetic buffer formulation to generate aptamers with high selectivity and affinity to noroxycodone and norhydrocodone, which also bind in natural urine.

The graphs below show the binding curves for aptamers to noroxycodone and norhydrocodone, obtained using microscale thermophoresis (MST). Aptamer H4LFD bound noroxycodone with an affinity (dissociation constant) of 43nM. A second aptamer, H5F4K, bound norhydrocodone with an affinity (dissociation constant) of 24nM.

binding graph noroxycodone atamer

Binding curve norhydrocodone







Base Pair’s patented multiplex aptamer selection process utilizing DNA barcoding speeds the aptamer selection process and enables the simultaneous development of aptamers to related opioids and metabolites. Proprietary algorithms are used to identify aptamers with high selectivity and affinity for target analytes.

​Base Pair has significant experience successfully generating aptamers that bind selectively to small molecules. Contact Base Pair today at or 832-230-5518 for more information.


1. Accessed 13 Dec 2016.
​2. Almasy, Steve. “Opioid epidemic is getting worse says CDC.” CNN. ​9 Dec 2016, Accessed 12 Dec 2016.
3. Liu, Y.W. et al. Levamisole-adulterated cocaine nephrotoxicity: Ultrastructural features. American Journal of Clinical Pathology. 2016;145(5):720-6.
​4. “Connecticut city warns of “tainted” heroin amid overdose spike.” Fox News Health. 24 June 2016, Accessed 13 Dec 2016.
​5. Drash, Wayne. “Report finds skyrocketing rate of babies going through opiate withdrawal.” CNN. 13 Dec 2016, Accessed 13 Dec 2016.
6. Villapiano, N.L.G. et al.  Rural and urban differences in neonatal abstinence syndrome and maternal opioid use. Journal of the Americal Academy of Medicine: Pediatrics. doi:10.1001/jamapediatrics.2016.3750. 12 Dec 2016.
7. “Drug of Abuse Tests.” FDA. 24 Feb 2016, Accessed 13 Dec 2016.
8. Leinwand-Leger, Donna. “Police carry special drug to reverse heroin overdoses.” USA Today. 3 Feb 2014,​. Accessed 13 Dec 2016.
​9. Walsh, Sandy. “FDA approves new hand-held auto-injector to reverse opioid overdose.” FDA. 3 April 2014, Accessed 13 Dec 2016.
10. Kuby J. Immunology. New York: W.H. Freeman; 1997.
11. Gani M, Coley J, Piron J, Humphreys AS, Arevalo J, Wilson IA, et al. Monoclonal antibodies against progesterone: effect of steroid-carrier coupling position on antibody specificity. The Journal of steroid biochemistry and molecular biology. 1994;48:277–82.
12. Moghaddam A, Lobersli I, Gebhardt K, Braunagel M, Marvik OJ. Selection and characterisation of recombinant single-chain antibodies to the hapten Aflatoxin-B1 from naive recombinant antibody libraries. Journal of immunological methods. 2001;254:169–81.
13. Jayasena, S. D. et al. An emerging class of molecules that rival antibodies in diagnostics. Clinical Chemistry. 1999;45(9):1628-50.
14. “Test strips for the rapid detection of cocaine.” Science Daily. 22 Nov 2006, Accessed 13 Dec 2016.
15. Ebrahimi, M. et al. Electrochemical impedance spectroscopic sensing of methamphetamine by a specific aptamer. Bioimpacts. 2012;2(2):91-954.  
16. Shi, Q., et al. Colorimetric and bare eye determination of urinary methylamphetamine based on the use of aptamers and the salt-induced aggregation of unmodified gold nanoparticles. Microchimica Acta. 2015;182(3):505-11.17.
17. 2016 National Drug Threat Assessment Summary. DEA. DEA-DCT-DIR-001-17. Nov 2016.
18. Cone, E.J., et al. Urine testing for norcodeine, norhydrocodone, and noroxycodone facilitates interpretation and reduces false negatives. Forensic Science International. 2010;198:58-61
​19. Fang, W.B., et al. Determination of oxycodone, noroxycodone, and oxymorphone by high-performance liquid chromatography-electrosprsay ionization-tandem mass spectrometry in human matrices: in vivo and in vitro applications. Journal of Analytical Toxicology. 2013;37(6):337-44.
​20. Valtier, S., et al. Excretion profile of hydrocodone, hydromorphone, and norhydrocofone in urine following single dose administration of hydrocodone to healthy volunteers. Journsal of Analytical Toxicology. 2012. doi:10.1093/jat/bks058.