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Quality control and lab accreditation

How can I assure proper quality control?

Guidance on how to maintain internal quality control is contained in each biomarker fact-sheet included on this site. Looking for an external standard to use? Try the National Institute of Standards and Technology (NIST) who offer a wide range of standards for laboratory quality control.

Why should my laboratory participate in an external quality assessment scheme?

External Quality Assessment (EQA) is an essential aspect of any laboratory operation. EQA provides laboratories with a independent means of assessing their analytical performance. The main aims of EQA include:

  • Maintain and improve analytical quality
  • Eliminate bias
  • Improve inter-laboratory agreement and raise standards
  • Detect equipment faults, identify reagent problems and review staff training
  • Initiate and evaluate corrective actions
  • Compare performance to different analytical methods

Ongoing monitoring of EQA performance will also help to reduce laboratory errors, produce accurate  results and most importantly improve health outcomes.

There are several international EQA schemes available to help laboratories meet their quality control requirements. See the links below (in no particular order) for more details and find a scheme suited to your requirements.

EQA schemes

CDC VITAL-EQA programme helps labs maintain and improve the quality of their measurements for biochemical indicators, The VITAL-EQA program helps labs maintain and improve the quality of their measurements for biochemical indicators for B-vitamins, CRP, iron, and vitamin A. If you are interested in participating in the program, or would simply like further information, write to

CDC VITAL-EQA programme

Randox International Quality Assessment Scheme (RIQAS) is one of the world’s largest global external quality assessment schemes help laboratories in >124 countries meet their quality requirements. Accredited to ISO/IEC 17043:2010. Paid service, with a wide number of options.

Randox International Quality Assessment Scheme (RIQAS)

Centre Toxicologique du Québec (CTQ) offers analytical expertise in toxicology and external quality assurance services based on inter-laboratory comparison programmes. Accredited to ISO/CEI 17025 of the Standards Council of Canada for human toxicology analysis, and to ISO/CEI 17043. Over 250 laboratories in 30 countries participate in their external quality assessment schemes. The CTQ can also provide standard reference materials upon request.

Centre Toxicologique du Québec (CTQ)

Quebec Multielement External Quality Assessment Scheme (QMEQAS), initiated in 1996, provides laboratories with multi-element capabilities, such as ICP-MS, with a wide range of analytes in human biological matrices that are not freeze dried. Participants receive three rounds per year, and biological matrices provided are hair, blood, serum and urine. Each matrix includes all analytes. Paid service, with a wide number of options.

Quebec Multielement External Quality Assessment Scheme (QMEQAS)

WEQAS, one of the largest External Quality Assessment providers in the UK, with over 50 years of experience in delivering global Quality Assurance Programmes in Laboratory Medicine.

UK NEQAS is a charitable consortium of external quality assessment laboratories, mostly evolved from NHS services England, Scotland, Wales and Northern Ireland. NEQAS have over 40 years experience in EQA and its clinical relevance across all disciplines (Immunology and Allergy, Cellular Pathology, Clinical Biochemistry, Haematology, Transfusion and Transplantation, Genetics, Virology and Microbiology).


College of American Pathologists (CAP) offer EQA and proficiency testing for international laboratories, and offer CAP accreditation following enrolment for 6 months or more. For more information, see their website or for specific questions, write to

College of American Pathologists (CAP)

LabCorp is a leading global life science company. Licensure/accreditation documentation may be requested to Paid service, with a wide number of options. For their test menu, consult this page.


ARUP Laboratories is a national clinical and anatomic pathology reference laboratory and a worldwide leader in innovative laboratory research and development. A nonprofit enterprise of the University of Utah, ARUP offers an extensive test menu of highly complex and unique medical tests.

ARUP Laboratories

German External Quality Assessment Scheme (G-EQUAS), have been carrying out an external quality assessment scheme and certification for occupational-medical and environmental-medical toxicological analyses in biological materials since 1982. Scheme, evaluation and certification are based on the guidelines of the German Medical Association (Bundesärztekammer). This scheme comprises the determination of toxicological parameters in blood, plasma/serum and urine samples of the occupational as well as the environmental concentration range. About 200 laboratories from more than 35 countries regularly participate in this scheme.

German External Quality Assessment Scheme (G-EQUAS)


Royal College of Pathologists of Australasia (RCPA) Chemical Pathology Quality Assurance Programme (QAP). RCPA QAP is accredited for compliance to ISO/IEC 17043:2010 Conformity assessment – General requirements for proficiency testing.

Royal College of Pathologists of Australasia (RCPA)


Note: International accreditation schemes to support quality control for specific nutrients, where applicable, are listed on each respective biomarker page.

Further reading

World Health Organization report: Laboratory Quality Standards and their Implementation (2011)


Common methods

Common methods

Practical guidance and methods that are common to the analysis of more than one nutrient.