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TCA Cycle Analysis Service

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What is TCA cycle?

The tricarboxylic acid (TCA) cycle, also known as the citric acid cycle or the Krebs cycle, is a crucial metabolic pathway in all aerobic organisms. And the TCA cycle plays a pivotal role in I) Energy production: the catabolism of carbohydrates, lipids, and proteins for ATP production. II) Intermediary metabolism: in addition to producing energy, the TCA cycle also serves as a central hub for the interconversion of metabolic intermediates. It is involved in the synthesis and breakdown of amino acids, fatty acids, and other important biomolecules. III) Redox balance: the TCA cycle helps to maintain the balance of reducing equivalents such as NADH and FADH2, which are important for various cellular processes, including the generation of ATP and the maintenance of cellular redox homeostasis. IV) Biosynthesis: certain intermediates of the TCA cycle serve as precursors for the biosynthesis of important compounds, such as amino acids, nucleotides. However, numerous reports have indicated that alterations in the TCA cycle play a pivotal role in oncogenesis and inflammation. Even the dysfunctions TCA cycle metabolites control physiology and disease. Therefore, studying the metabolism of the TCA cycle offers valuable insights into cellular respiration, energy generation, and overall biological system functionality. Through TCA cycle analysis, one can enhance their understanding of metabolic pathway regulation, identify potential dysfunctions or abnormalities, and gain deeper insights into various physiological and pathological conditions.

TCA Cycle Analysis ServiceFigure 1. Tricarboxylic acid (TCA) cycle [1].

TCA Cycle Analysis Service in Creative Proteomics

Revealing a more profound comprehension of the differential regulation and configuration of the TCA cycle in diverse contexts will offer valuable insights into how this pathway is finely tuned to meet the specific demands of different cellular states. With over a decade of experience in metabolomics services, Creative Proteomics can provide superior service for analyzing TCA cycle metabolites. The qualitative and quantitative data and reports of metabolites can be delivered with precision and accuracy. For typical analysis methods in Creative Proteomics, the process primarily involves: I) Experimental design, such as the selection of appropriate extraction and instrumental techniques. II) Sample collection. III) Target metabolites extraction. IV) Data acquisition using LC-MS/MS. V) Statistical analysis, encompassing biomarker analysis, pathway analysis, and biological interpretation. VI) Report delivery. Most importantly, the execution of all processes can be efficiently and accurately accomplished within a limited timeframe.

TCA Cycle Analysis ServiceFigure 2. The general workflow of TCA cycle metabolites identification [2].

The field of metabolomics research is significantly advanced by Creative Proteomics, a prominent company in this domain. The HPLC-MS/MS methods developed by Creative Proteomics is highly sensitive, reliable, and accurate for theidentification and quantification of metabolites in the TCA cycle. Our proficient researchers enable precise quantification of both targeted and untargeted TCA cycle metabolites, facilitating the measurement of absolute concentrations and assessment of relative abundance in diverse biological samples or experimental conditions. Additionally, we excel in isotopic tracer experiments, enabling high-throughput analysis to determine turnover rates of metabolites within the TCA cycle.

TCA Cycle Metabolites Quantified in This Service
Citric acidDL-α-OH-glutaric acidErythrose-4-P
Fumaric acidGDPGTP
Glycolic acidIsocitric acidLactic acid
Malic acidMalonyl-CoAMannose-1-P
Phosphoenolpyruvate (PEP)Pyruvic acidRibose-5-P
Ribulose-5PSedoheptulose-7PSuccinic acid
Xylose-5-Pα-Ketoglutaric acid

Technological superiority

1. Professional detection and analysis capability: Experienced research team, strict quality control system, together with ultra-high resolution detection system and professional data pre-processing and analysis capability, ensure reliable and accurate data.

2. Reproducible: Obtain consistent and reproducible inter- and intra- assay results for data analysis.

3. High veracity of data: With isotope correction by internal standard and absolute quantification by external standard, absolute concentration data provided with cost-effective, short-period, and standard curve R2>0.99.

4. High resolution and sensitivity: AB SCIEX QTRAP 6500 Plus, AB SCIEX QTRAP 5500, et al.

5. Established a relatively perfect database.

Applications of TCA Cycle Metabolism Analysis

1. Clinical diseases: biomarker discovery, disease mechanisms, metabolic disorders.

2. Food industry: food nutrition, clinical nutrition.

3. Livestock: Scientific feeding, disease prevention and development research.

4. Medicine: Drug development, evaluation of toxic and side effects.

5. Environmental toxicology.

Samples Requirement

  • Normal Volume: 200 μL serum/plasma; 200 mg tissue, 2×107 cells
  • Minimal Volume: 50 μL serum/plasma; 50 mg tissue, 5×106 cells.
  • Any other samples such as body fluid (urine, cerebral spinal fluid, et al.), feces, cell culture medium supernatant.

Results Delivery

1. A detailed technical report will be provided at the end of the whole project, including the experiment procedure, MS/MS instrument parameters, etc.

2. Raw data and data analysis results (multivariate statistical analysis, pathway analysis, etc.).

  • Analytes are reported as μM or μg/mg (tissue), and variable-coefficient are generally<10%
  • The name of the analytes, abbreviation, formula, molecular weight, and CAS# would also be included in the report.

How to place an order

At Creative Proteomics, many excellent and experienced experts will optimize the experimental protocol according to your requirement and guarantee the high-quality results for TCA Cycle Metabolites Analysis Service. Please feel free to contact us by email to discuss your specific needs. Our customer service representatives are available 24 hours a day, from Monday to Sunday.


  1. Sánchez-García FJ, Pérez-Hernández CA, Rodríguez-Murillo M, et al. The Role of Tricarboxylic Acid Cycle Metabolites in Viral Infections. Frontiers in cellular and infection microbiology. 2021 Sep 14;11:725043.
  2. Du X, Yang L, Kong L, et al. Metabolomics of various samples advancing biomarker discovery and pathogenesis elucidation for diabetic retinopathy. Frontiers In Endocrinology. 2022 Oct 27;13:1037164.

Changes in TCA cycle and TCA cycle-related metabolites in plasma upon citric acid administration in rats

Journal: Heliyon

Published: 2021

Main Technology: Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).


Recent studies have reported that plasma levels of tricarboxylic acid (TCA) cycle metabolites and TCA cycle-related metabolite change in patients with chronic fatigue syndrome (CFS) and in healthy humans after exercise. Exogenous dietary citric acid has been reported to alleviate fatigue during daily activities and after exercise. However, it is unknown whether dietary citric acid affects the plasma levels of these metabolites. Therefore, the present study aimed to investigate the effects of exogenously administered citric acid on TCA cycle metabolites and TCA cycle-related metabolites in plasma. Sprague-Dawley rats were divided into control and citric acid groups. We evaluated the effect of exogenous dietary citric acid on the plasma TCA cycle and TCA cycle-related metabolites by metabolome analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS). TCA cycle metabolites, including plasma citrate, cis-aconitate, and isocitrate, were significantly elevated after exogenous administration of citric acid. Anaplerotic amino acids, which are converted to TCA cycle metabolites, such as serine, glycine, tryptophan, lysine, leucine, histidine, glutamine, arginine, isoleucine, methionine, valine, and phenylalanine, also showed significantly elevated levels. Citric acid administration significantly increased the levels of initial TCA cycle metabolites in the plasma. This increase after administration of citric acid was shown to be opposite to the metabolic changes observed in patients with CFS. These results contribute novel insight into the fatigue alleviation mechanism of citric acid.

TCA Cycle Analysis ServiceFigure 1. Plasma levels of TCA cycle metabolites in rats measured by LC-MS/MS analysis.

TCA Cycle Analysis ServiceFigure 2. Plasma levels of anaplerotic amino acids of TCA cycle metabolites in rats measured by LC-MS/MS analysis.

* For Research Use Only. Not for use in diagnostic procedures.
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