Total Thiol Assay Kit


Thiols, also known as mercaptans, are a class of organic compounds that contain a sulfhydryl group (–SH) composed of a sulphur atom and a hydrogen atom attached to a carbon atom. The plasma thiol pool is mainly formed by albumin thiols, protein thiols and slightly formed by low-molecular-weight thiols such as cysteine (Cys), cysteinylglycine, glutathione, homocysteine and γ- glutamylcysteine. 
Thiols (RSH) can undergo oxidation reaction via oxidants and form disulphide (RSSR) bonds. A disulphide bond is a covalent bond; the linkage is also called a SS-bond or disulphide bridge. Under conditions of oxidative stress, the oxidation of Cys residues can lead to the reversible formation of mixed disulphides between protein thiol groups and low-molecular-mass thiols. The formed disulphide bonds can again be reduced to thiol groups; thus, dynamic thiol–disulphide homeostasis is maintained.

Thiols, also known as mercaptans, are a class of organic compounds that contain a sulfhydryl group (–SH) composed of a sulphur atom and a hydrogen atom attached to a carbon atom. The plasma thiol pool is mainly formed by albumin thiols, protein thiols and slightly formed by low-molecular-weight thiols such as cysteine (Cys), cysteinylglycine, glutathione, homocysteine and γ- glutamylcysteine. 

Thiols (RSH) can undergo oxidation reaction via oxidants and form disulphide (RSSR) bonds. A disulphide bond is a covalent bond; the linkage is also called a SS-bond or disulphide bridge. Under conditions of oxidative stress, the oxidation of Cys residues can lead to the reversible formation of mixed disulphides between protein thiol groups and low-molecular-mass thiols. The formed disulphide bonds can again be reduced to thiol groups; thus, dynamic thiol–disulphide homeostasis is maintained.  

Dynamic thiol disulphide homeostasis status has critical roles in antioxidant protection, detoxification, signal transduction, apoptosis, regulation of enzymatic activity and transcription factors and cellular signalling mechanisms. Moreover, dynamic thiol disulphide homeostasis is being increasingly implicated in many disorders. There is also a growing body of evidence demonstrating that an abnormal thiol disulphide homeostasis state is involved in the pathogenesis of a variety of diseases, including diabetes [1-3], cardiovascular disease [4-10], cerebrovascular disase [11],  malignacies [12], ankylosing spondylitis [13], preeclampsia [14,15], Alzheimer's disease [16], migraine  [17], infections [18,19],   and various disorders. Therefore, determination of dynamic thiol disulphide homeostasis can provide valuable information on various normal or abnormal biochemical processes.  This easy, practical, fully automated and also optionally manual spectrophotometric assay can be used to determine plasma dynamic thiol/disulphide homeostasis.

Dynamic thiol/disulphide homeostasis in patients with newly diagnosed primary hypertension

I Ates, N Ozkayar, B Inan, FM Yilmaz… - Journal of the …, 2016 - ashjournal.com
… determining native and total thiols, disulphide level, disulphide/total thiol percent ratios, native
thiol/total thiol percent ratios, and disulfide/native thiol percent ratios were calculated. 8 x8Erel,
O. and Neselioglu, S. A novel and automated assay for thiol/disulphide homeostasis …  Cited by 16 Related articles All 6 versions

Relationship between total thiol status and thrombocytopenia in patients with Crimean-Congo hemorrhagic fever

R Guner, MA TasyaranS Keske… - … Asian Journal of …, 2012 - search.proquest.com
… Serum TOS levels were determined using a commer— cial available kit (Rel Assay Diagnostic,
Turkey … may be related to these interactions (Table 2). In conclusion, the total thiol status
significantly … in this disease, it may also be related to thiol/disulfide homeostasis moving to the …  Cited by 5 Related articles All 9 versions

[PDF] Advanced oxidation protein products, total thiol levels and total oxidant/antioxidant status in patients with nash

M Baskol, K Dolbun Seckin… - Turk. J …, 2014 - pdfs.semanticscholar.org
… Assay of total oxidant capacity Total oxidant status levels were measured using commercially
available kits (Rel Assay) … AOPP, total thiol, TOS, TAS in NASH … Redox environment of the cell
as viewed through the redox state of the glutathione disulfide/glutathione couple …  Cited by 5 Related articles All 7 versions [HTML] tandfonline.com

A retrospective controlled study of thiol disulfide homeostasis as a novel marker in Crimean Congo hemorrhagic fever

ZK Tufan, I Hasanoglu, S Kolgelier, M Alisik… - Redox …, 2017 - Taylor & Francis
… upon the organism's oxidant–antioxidant balance; therefore, a dynamic thiol disulfide homeostasis
(TDH) exists … However, as the two previous studies were based only on total thiol levels, the … Erel
O, Neselioglu S. A novel and automated assay for thiol/disulphide homeostasis …  Cited by 4 Related articles All 3 versions

A comprehensive study of oxidative stress in sudden hearing loss

F GulT Muderris, G Yalciner, E Sevil, S Bercin… - European Archives of …, 2017 - Springer
… levels of total antioxidant status were measured using the TAS Kit (Rel Assay Diagnostics, Ankara …
status, OXI oxidative stress index, -SH native thiol, -SH + -S–S- total thiol, -S–S … logistic regression
was performed to ascertain the effects of age, gender, disulphide levels, and TOS …  Cited by 3 Related articles All 5 versions

Disulfide stress in carbon monoxide poisoning

M Ergin, M Caliskanturk, A Senat, O Akturk, O Erel - Clinical biochemistry, 2016 - Elsevier
… PON and ARES serum activity were measured by using commercially available kits (Rel Assay
Diagnostics, Gaziantep … SH + –S–S–) and (–S–S–/–SH)], and decreased native thiol/total thiol
ratios [SH/(–SH + –S–S–)] indicated that the thiol-disulfide homeostasis was impaired …  Cited by 3 Related articles All 6 versions

A novel biomarker explaining the role of oxidative stress in exercise and l-tyrosine supplementation: thiol/disulphide homeostasis

Y KayacanH YazarEC Kisa… - Archives of physiology …, 2017 - Taylor & Francis
… were again micro-centrifuged and the study test parameters were studied in the Rel Assay
Diagnostics kits … A novel and automated assay for thiol/disulphide homeostasis … Total thiol (–SH +
–S–S–) and native thiol (–SH) concentrations in the samples were measured by using …  Related articles All 4 versions

[HTML] Thiol Disulfide Homeostasis in Schizophrenic Patients Using Atypical Antipsychotic Drugs

HO Dogan, EE Ersan, H Aydin, S Erdoğan… - Clinical …, 2018 - ncbi.nlm.nih.gov
… equivalent/L. TOS levels were measured using commercially available colorimetric kits (Rel Assay
Diagnostic … reduction of the DTNB and further reduction of the formed disulphide bond, which … When
the results obtained by subtracting native thiol from total thiol were divided into …  All 9 versions

[PDF] A comparative study of the oxidative stress indices of children with autism and healthy children

Ç UĞUR, H TUNCA, E SEKMEN, ÖŞ ÜNERİ, M ALIŞIK… - researchgate.net
… iii. Measurement of TOS levels: A Rel Assay Kit was used to assess serum TOS levels … Total
thiol-SH 453.97±61.50 467.27±60.93 -0.686 0.496 … and thiol levels between children with ASD
and healthy individuals, no measurable differ- ence was found in TOS and disulphide levels …  Oxidative injury associated with stenting of asymptomatic carotid artery stenosis.
E Saraçoğlu, E Vuruşkan, Y Çekici… - VASA. Zeitschrift fur …, 2017 - econtent.hogrefe.com
… The Rel Assay TAS and TOS kits (Rel Assay Diagnostics, Gaziantep, Turkey) were used … and
thiol groups oxidize to form re- versible disulphide bonds, and the thiol-disulphide bond balance …
Receiver operating characteristics curves of Δ total thiol, Δ TAS, Δ TOS for neurologic …  Related articles All 4 versions


Reagent 1A1 x 1 ml
Reagent 1B1 x 15 ml
Reagent 21 x 30 ml
Reagent 31 x 8 ml


1. Ates I, Kaplan M, Yuksel M, Mese D, Alisik M, Erel Ö, Yilmaz N, Guler S. Determination of thiol/disulphide homeostasis in type 1 diabetes mellitus and the factors associated with thiol oxidation. Endocrine. 2016 Jan;51(1):47-51. doi: 10.1007/s12020-015-0784-6. Epub 2015 Nov 7. PubMed PMID: 26547218.

2. Ates I, Kaplan M, Inan B, Alisik M, Erel O, Yilmaz N, Guler S. How does thiol/disulfide homeostasis change in prediabetic patients? Diabetes Res Clin Pract. 2015 Nov;110(2):166-71. doi: 10.1016/j.diabres.2015.09.011. Epub 2015 Sep 24. PubMed PMID: 26421363.

3. Ozler S, Oztas E, Caglar AT, Uygur D, Ergin M, Erel O, Danisman N. Thiol/disulfide homeostasis in predicting adverse perinatal outcomes at 24-28 weeks of pregnancy in gestational diabetes. J Matern Fetal Neonatal Med. 2016 Feb 24:1-6. [Epub ahead of print] PubMed PMID: 26769102.

4. Kundi H, Ates I, Kiziltunc E, Cetin M, Cicekcioglu H, Neselioglu S, Erel O, Ornek E. A novel oxidative stress marker in acute myocardial infarction; thiol/disulphide homeostasis. Am J Emerg Med. 2015 Nov;33(11):1567-71. doi: 10.1016/j.ajem.2015.06.016. Epub 2015 Jun 14. PubMed PMID: 26143314.

5. Kundi H, Erel Ö, Balun A, Çiçekçioğlu H, Cetin M, Kiziltunç E, Neşelioğlu S, Topçuoğlu C, Örnek E. Association of thiol/disulfide ratio with syntax score in patients with NSTEMI. Scand Cardiovasc J. 2015 Apr;49(2):95100. doi: 10.3109/14017431.2015.1013153. Epub 2015 Mar 2. PubMed PMID: 25658436.

6. Altiparmak IH, Erkus ME, Sezen H, Demirbag R, Kaya Z, Sezen Y, Gunebakmaz O,  Asoglu R, Besli F, Neselioglu S, Erel O. Evaluation of thiol levels, thiol/disulfide homeostasis and their relation with inflammation in cardiac syndrome X. Coron Artery Dis. 2016 Jun;27(4):295-301. doi: 10.1097/MCA.0000000000000362. PubMed PMID: 26928883.

7. Kundi H, Gok M, Cetin M, Kiziltunç E, Topcuoglu C, Neşelioğlu S, Erel O, Ulusoy FV. Association of thiol disulfide homeostasis with slow coronary flow. Scand Cardiovasc J. 2016 Mar 11:1-5. [Epub ahead of print] PubMed PMID: 26891417.

8. Ateş İ, Ozkayar N, Altay M, Yilmaz FM, Topçuoğlu C, Alışık M, Erel Ö, Dede F. Is disulphide/thiol ratio related to blood pressure in masked hypertension? Clin  Exp Hypertens. 2016;38(2):150-4. doi: 10.3109/10641963.2015.1060995. Epub 2015Sep 29. PubMed PMID: 26418425.

9. Erkus ME, Altiparmak IH, Akyuz AR, Demirbag R, Sezen Y, Gunebakmaz O,Neselioglu S, Erel O. The association between plasma thiol levels and left ventricular diastolic dysfunction in patient with hypertension. Scand J Clin Lab Invest. 2015;75(8):667-73. Epub 2015 Aug 7. PubMed PMID: 26252832.

10.  Ates I, Ozkayar N, Inan B, Yilmaz FM, Topcuoglu C, Neselioglu S, Erel O, Dede F, Yilmaz N. Dynamic thiol/disulphide homeostasis in patients with newly diagnosed primary hypertension. J Am Soc Hypertens. 2016 Feb;10(2):159-66. doi: 10.1016/j.jash.2015.12.008. Epub 2015 Dec 15. PubMed PMID: 26725016.

11. Bektas H, Vural G, Gumusyayla S, Deniz O, Alisik M, Erel O. Dynamic thiol-disulfide homeostasis in acute ischemic stroke patients. Acta Neurol Belg.  2016 Jan 18. [Epub ahead of print] PubMed PMID: 26782823.

12. Guney T, Kanat IF, Alkan A, Alisik M, Akinci S, Silay K, Neselioglu S, Dilek I, Erel O. Assessment of serum thiol/disulfide homeostasis in multiple myeloma patients by a new method. Redox Rep. 2016 May 19:1-6. [Epub ahead of print] PubMed PMID: 27198712.

13. Dogru A, Balkarli A, Cetin GY, Neselioglu S, Erel O, Tunc SE, Sahin M. Thiol/disulfide homeostasis in patients with ankylosing spondylitis. Bosn J Basic Med Sci. 2016 May 16. doi: 10.17305/bjbms.2016.1001. [Epub ahead of print] PubMed PMID: 27186972.

14. Korkmaz V, Kurdoglu Z, Alisik M, Cetin O, Korkmaz H, Surer H, Erel O. Impairment of thiol-disulfide homeostasis in preeclampsia. J Matern Fetal Neonatal Med. 2016 Mar 3:1-6. [Epub ahead of print] PubMed PMID: 26828694.

15. Ozler S, Erel O, Oztas E, Ersoy AO, Ergin M, Sucak A, Neselioglu S, Uygur D,  Danisman N. Serum Thiol/Disulphide Homeostasis in Preeclampsia. Hypertens Pregnancy. 2015 Nov;34(4):474-485. Epub 2015 Nov 20. PubMed PMID: 26588703.

16. Gumusyayla S, Vural G, Bektas H, Deniz O, Neselioglu S, Erel O. A novel oxidative stress marker in patients with Alzheimer's disease: dynamic thiol-disulphide homeostasis. Acta Neuropsychiatr. 2016 Apr 4:1-6. [Epub ahead of print] PubMed PMID: 27040443

17. Gumusyayla S, Vural G, Bektas H, Neselioglu S, Deniz O, Erel O. A novel oxidative stress marker in migraine patients: dynamic thiol-disulphide homeostasis. Neurol Sci. 2016 May 3. [Epub ahead of print] PubMed PMID: 27142446.

18. Tufan ZK, Hasanoglu I, Kolgelier S, Alisik M, Ergin M, Yilmaz GR, Tasyaran MA, Erel O, Guner R. A retrospective controlled study of thiol disulfide homeostasis as a novel marker in Crimean Congo hemorrhagic fever. Redox Rep. 2016 May 9:1-5. [Epub ahead of print] PubMed PMID: 27159644.

19. Kara SS, Erel O, Demirdag TB, Cura Yayla BC, Gulhan B, Neselioglu S, Polat M, Kalkan G, Tapisiz A, Tezer H. Alteration of thiol-disulphide homeostasis in acute tonsillopharyngitis. Redox Rep. 2016 Apr 20:1-5. [Epub ahead of print] PubMed PMID: 27096391.

20. Erel O, Neselioglu S. A novel and automated assay for thiol/disulphide homeostasis. Clin Biochem. 2014 Dec;47(18):326-32. doi: 10.1016/j.clinbiochem.2014.09.026. Epub 2014 Oct 7. PubMed PMID: 25304913. 

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