Specialists in Stable Isotope & Metabolite Synthesis

ISO 9001


Isotope Labeled Metabolites

Isotope labeling is a vital tool for clarifying the flow of a particular element through a cell’s metabolic pathway. To create a stable product, a given isotopic label is fed into a cell, allowing it to grow until it reaches a steady state. Once the output pattern of the isotope labeled metabolite is determined, it can provide important data—helping provide insight into flux reactions within a cell and rates of conversions from reactants to products.   

The use of Isotope labeled metabolites has been critical to research developments in a variety of fields, including environmental analysis, bio-med, biochemistry and physics. Through the use of tracer methodology these compounds help researchers study the degradation of cells in both healthy and diseased environments. Isotope labeled metabolites are perfect for studying metabolic flux because they mimic the natural, endogenous metabolite. 

Isotope labeled metabolites for pesticide research

Pesticides can produce carcinogenic pollutants into the environment like Dioxins and Furans. To study and fight the effects of Dioxin and Furan, labeled standards for each have been developed, including: Carbon 13 Chlorodioxin Standards like Dibenzo-p-dioxin (50 ± 5 µg/mL in Nonane) and Octachlorodibenzofuran (50 ± 2.5 µg/mL in Nonane). The preparation of these solutions starts with the complete synthesis of each isomer from known intermediates.

Labeled BDE Metabolites

Used in flame retardants, Brominated Diphenyl Ethers (BDE) has become a chemical of high environmental concern and study. Synthesized Carbon 13 BDEs have been used to analyze and set standards for BDE safety.

Labeled metabolites for cancer studies

As the need to investigate cancer progression at the cellular level increases, tracing and measuring labeled metabolites such as amino acids, lipids, glucose and lactate have become critical practices. The use of Carbon 12 and Carbon 13 labeled amino acids in cell cultures has furthered prostate cancer research in recent years.

It is important that any Isotope Labeled Metabolite is developed with extensive testing to ensure the utmost in isomeric purity, isotope enrichment and absolute concentration. Industry standards have been set and should be met at all times.

All metabolomic chemistries currently synthesized by IsoSciences catalog can be found here.If you are unable to find the desired metabolome in our catalog, please contact us by email or phone (610-337-3762) we will be more than happy to provide a quote on custom synthetic work.

Isotope Labeled Metabolites


Labeled 25-hydroxyvitamin

25-hydroxyvitamin-d3 (CAS 19356-17-3) is a prehormone created by the liver by the cholecalciferol 25-hydroxylase enzyme during hydroxylation of vitamin D3. It is converted in kidneys into the secosteroidhormone calcitriol, the active form of vitamin D, by the 25(OH)D-1a-hydroxylase enzyme. Similarly, it can be converted in kidneys into 24-hydroxycalcidiol through 24-hydroxylation. The name 25-hydroxyvitamin-d3 may also be abbreviated to 25(OH)D, or it may be known as calcidiol, 25-hydroxycholecalciferol, and its international nonproprietary name (INN) of calcifediol.

25-hydroxyvitamin-d3 was first identified by Michael F. Holick, a translation physician-scientist from U.S., and is now measured by physicians across the globe in order to determine the amount of vitamin D in body of a patient through a 25-hydroxy vitamin D blood test. The concentration of 25-hydroxyvitamin-d3 in the blood is considered the best measure of vitamin D status in an individual.

Labeled 25-hydroxyvitaminThe test is used to determine whether a patient is experiencing a vitamin D deficiency and to diagnose the tendency of risk of such a condition. Patients suffering from osteoporosis, malabsorption, chronic kidney disease, obesity, and some infections are especially prone to vitamin D deficiencies and so are particularly suited to a such screening. The results of the blood test are then used to determine the appropriate treatment, which may consist of aggressive therapies. Although people living at high latitudes or where there is limited sun exposure often experience vitamin D deficiency, the test is not suitable for entire populations. Lower risk patients are more likely to be advised to take an over-the-counter vitamin D supplement than to undergo the blood test.

A normal level of 25-hydroxyvitamin-d3 will depend on external factors such as age and geographical location. MedlinePlus puts normal range at 30.0 to 74.0 nanograms per milliliter, while another study published in the Journal of Nutrition defined less than 32 nanograms per milliliter as vitamin D deficiency. Furthermore, it is possible for 25-hydroxyvitamin-d3 levels to be too high. A study of 25,000 volunteers, conducted by the University of California, found that those with high levels of 25-hydroxyvitamin-d3 resulted in a higher risk of colon cancer at one-fifth of normal rates.

In order to undertake mass spectrometry studies we sell the deuterium labeled 25-hydroxyvitamin-d3 which is available in 1 milligram or 5 milligram orders at 98 percent purity or below. It is considered to be a hazardous substance but holds no DEA certification.

We are proud to offer a selection of stable labeled vitamins. For your convenience, we sell unlabeled vitamins alongside our list of labeled vitamins. Our selection includes CertiMass™ Reference Standards, which are standard solutions for many of our premier compounds

If you are unable to find the desired vitamin in our catalog, please contact us by email or phone (610-337-3762) we will be more than happy to provide a quote on custom synthetic work.

Labeled 25-hydroxyvitamin | 25-hydroxyvitamin Labeling



Labeled Aldosterone

Aldosterone (CAS 52-39-1)  is a hydroxycorticosteroid hormone produced by the adrenal cortex. Due to its chemical structure, aldosterone belongs to the polycyclics and pregnenediones molecule classes. The natural synthesis of Aldosterone takes place exclusively in the outer region of the adrenal cortex, called "zona glomerulosa", and begins with a reaction that converts cholesterol to pregnenolone and further to progesterone. The progesterone that results is then hydroxylated, yielding deoxycorticosterone, or DOC. The final steps in the synthesis of this hormone involve the conversion of DOC into corticosterone, followed by two oxidation reactions. The production of aldosterone only begins after the body receives stimuli. The main stimulus that initiates the production process is a compound called angiotensin II. Other stimuli include high blood levels of potassium (hyperkalemia) or low levels of sodium (hyponatremia), as well as ACTH, serotonin, and endothelin.

Labeled AldosteroneThe importance of aldosterone derives from its involvement in the sodium and potassium balance. The mineralocorticoid hormone enhances the reabsorption of sodium and water and the release of potassium, thus being considered the "salt-retaining hormone". It also enhances the reabsorption of the chloride ion along with sodium, ensuring that the body's electrochemical balance is maintained. An aldosterone level that is higher than normal leads to low levels of potassium and increased blood pressure. An abnormally low level of aldosterone is also undesirable, as it  can cause low blood pressure and an elevated pulse, symptoms that become more unpleasant while the individual is standing. Other symptoms of low aldosterone include posture-induced dizziness, palpitations, and salt-cravings. In severe cases, the levels of sodium and potassium will appear abnormal on the blood tests.

Aldosterone levels are low in patients who suffer from Addison's disease and higher than normal in patients that have Conn's syndrome. Other conditions that are related to abnormal levels of aldosterone include congenital adrenal hyperplasia, hyporeninemic hypoaldosteronism, primary or secondary hyperaldosteronism, and Bartter's syndrome. In some cases, an abnormal blood level of aldosterone may be caused by extreme diets that are either very high or very low in sodium. It can also indicate kidney or liver disease, heart failure, or preeclampsia.

Most aldosterone blood tests now utilize a mass spectrometry based technique to determine the overall aldosterone level. As such IsoSciences offers an unlabeled form and two labeled forms of aldosterone - d4 and a d7.

5093UNL         Aldosterone (unlabeled)

5093                Aldosterone (d7)

11214              Aldosterone (d4)

We are proud to offer a selection of stable labeled hormones. For your convenience, we sell unlabeled hormones alongside our list of labeled hormones. Our selection includes CertiMass™ Reference Standards, which are standard solutions for many of our premier compounds

If you are unable to find the desired hormone in our catalog, please contact us by email or phone (610-337-3762) we will be more than happy to provide a quote on custom synthetic work.

Labeled Aldosterone | Aldosterone Labeling


Stable Isotope Labeling

Stable isotope labeling consists of using non-radioactive isotopes as tracers in biochemical systems.  The most obvious benefit is the non-hazardous nature of the label and the minimized need for protective measures.  There is a cost benefit associated with running a non-radioactive lab in addition to removing the fatigue and stress to personnel that occurs when working with hazardous materials.

The use of stable isotopes in research is well established through studies of naturally occurring isotopes.  Migratory patterns of land and water based species are traced using isotope ratios unique to individual feeding areas.   Transmission of bacteria can also be followed using natural isotope ratios in host food sources.  Just as naturally occurring compounds with a heavy load of stable isotope are not detrimental to organisms, artificially labeled compounds are similarly utilized without altering physiologic or biochemical functions.

Compounds labeled with stable isotopes maintain physico-chemical properties, allowing consistent interactions within biochemical pathways.  Labeled products closely mimic natural metabolites, allowing for accurate metabolic assay measurements without introducing increased experimental noise.  Methods are applicable to cells as well as higher organisms ranging from insects to mammals.

Labeled compounds are ideal for drug metabolism studies, allowing detection of the whole compound as well as the ability to follow break-down products.  When combined with nuclear magnetic resonance and mass spectroscopy, a detailed understanding of compound absorption, distribution, metabolism and excretion can be quickly and accurately obtained.  Similar methods are used to study the toxicity of protein substances, chemicals or drugs.

Host-parasite relationships including those parasites that cause malaria, toxoplasmosis and Leishmaniasis are investigated using labeled compounds.  Parasite and host cells are labeled to determine pathways involved in parasite infectivity and potential drug activity. Similar methods are applicable to bacterial and viral studies.

Stable isotope labeling can be undertaken on a custom basis by our synthetic team, to discuss further, please contact us by email or phone (610-337-3762) we will be more than happy to provide a quote on custom synthetic work. All stock chemistries currently synthesized by IsoSciences catalog can be found here.

Stable Isotope Labeling


Tritium Labeling

Fast Turnaround Tritium Labeling Laboratory

With over 80 years of experience in radioisotope labeling, the IsoSciences fast turnaround tritium labeling facility stands out as one of the most experienced labs in the industry. In particular our experience has been substantially with multiple nuclei; 3H, 14C, 125I, 11C, 18F, 77Br, and 195Au HHH. Incorporation of these radioisotope nuclei has been broadly used in both academic molecules but also in molecules considered proprietary within the pharmaceutical industry. Importantly, the IsoSciences radioisotope team also has the full synthetic support of our world renowned stable isotope synthesis lab, adding many advanced degree chemists with specialties in sugar chemistries, heterocyclics, annulations, natural products, APIs and toxin syntheses.

IsoSciences recognizes the importance of correct equipment in order to undertake the broad range of tritium labeling and functional group conversions necessary to generate the final molecules required by our partners. Core equipment available at our Monmouth Junction (NJ) facility includes:

  • RC Tritec Tritium Manifold
  • Agilent 1100 (TQD) HPLC with a Packard Radiomatic 150TR Flow Scintillation Analyzer
  • Packard Tricard 2100 TR Liquid Scintillation Counter
  • Thermo TSQ Quantum Classic LC/MS/MS

Synthetic capabilities are a primary consideration in the IsoSciences’ tritium labeling facility. However we have placed an equal importance on the analysis tools available to our staff. As more labs look to outsource their tritium labeling work there has been a greater emphasis on generating complete support documentation that allows a partner to regularly accept material without additional QC analysis. As such we have developed a comprehensive set of analytical tools to provide tailored data packages. Our analytical tools include:

  • NMR – Varian 300MHz (multi-nuclei)
  • HPLC/GC (including prep HPLC)
  • Mass Spectroscopy
    • Agilent LC-MS
    • Waters Acuity LC-MS
    • GC-MS

Our experienced analytical group is able to use these instruments coupled with orthogonal methodologies and specific activity determinations in order to provide accurate and conclusive evidence to supportive final product delivery.

Our team is ready to discuss your needs and reliably deliver your compound with time and cost efficiency. Please view our current catalog or contact the radiolabeling group at 610-337-3762 or This e-mail address is being protected from spambots. You need JavaScript enabled to view it .


Tritium Labeling | Tritium


Tritiation Lab

Tritiation at IsoSciences

The radiolabeling lab at IsoSciences has extensive capability in the synthesis and purification of a broad variety of tritiated molecules. All of our clients receive the benefit that stems from a team of organic chemists directed by management with over 50 years experience synthesizing radiolabeled materials. Our breadth of experience covers fast turnaround tritiation experiments to produce drug APIs, small molecules, proteins, polymers and other molecules of biological interest including hormones, steroids, nucleosides and oligonucleotides.

No matter how complex the tritiation project, IsoSciences’ team has the necessary experience to complete the task. Whether it is a simple single-step tritiation to multi-step complex synthesis our diverse team has the ability to complete the project. Our expert chemists can design a tritium labeling route based on your needs. With over a decade of experience handling sensitive isotope labeled/unlabeled materials in small quantities, our clients are assured that any raw materials supplied will be appropriately handled, and products delivered will be of the highest quality.

IsoSciences’ production and quality control is internally organized and rigorously overseen using ISO9001:2008 guidelines. Our external certification from BSI means clients can rest assured that full documentation and traceability exists as and when auditing and related processes need full documentation.

If intellectual property is a concern, please note that IsoSciences currently has over 100 NDA/CDAs in place with major organizations and are willing to enter into additional agreements as clients believe necessary.

Please contact our radiolabeling department by This e-mail address is being protected from spambots. You need JavaScript enabled to view it or phone (610-337-3762) to discuss how IsoSciences can rapidly fulfill your radiolabeling needs.


Tritium Labeling

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