What Is NABL Accreditation? Why It Matters for Your Blood Tests and Health

A reliable laboratory report is not simply the product of a sophisticated machine. It is the outcome of trained professionals, scientifically established methods, quality-control systems and careful attention at every stage of testing.

When choosing a pathology laboratory, patients commonly compare prices, convenience, reporting times and reputation. But there is another important question:

How can you know whether a laboratory follows recognised standards of quality and technical competence?

One important way is to check for NABL accreditation.

The National Accreditation Board for Testing and Calibration Laboratories (NABL) provides independent accreditation to medical laboratories against internationally recognised requirements, including ISO 15189:2022.

At Dr. Bhasin's Lab in Greater Kailash Part 1, New Delhi, we have participated in the accreditation system since 2008, while our commitment to calibration, internal quality control and external quality assessment began even earlier.

In this article, we explain what accreditation means, why it matters to patients, what published scientific research tells us about laboratory quality, and how those principles translate into everyday laboratory practice.

What Is NABL Accreditation?

NABL stands for the National Accreditation Board for Testing and Calibration Laboratories.

NABL is a constituent board of the Quality Council of India (QCI). It provides independent accreditation services to laboratories and other eligible organisations.

For medical laboratories, accreditation is based on ISO 15189:2022, together with applicable NABL requirements.

ISO 15189:2022 is an international standard that specifies requirements for quality and competence in medical laboratories. It applies to laboratories developing their management systems, assessing technical competence and demonstrating that their activities meet the required standards.

In practical terms, NABL accreditation demonstrates that a laboratory has undergone independent assessment of its technical competence and quality management arrangements for specified medical testing activities.

An essential distinction is that accreditation applies to a defined Scope of Accreditation. It does not automatically include every examination offered by a laboratory.

Scientific reference: International Organization for Standardization. ISO 15189:2022 — Medical laboratories: Requirements for quality and competence. Official ISO publication.

Why Does Laboratory Quality Matter to Patients?

A laboratory report can contribute to decisions about diagnosis, treatment, medication, surgery and the monitoring of disease.

For example, HbA1c measurements may support diabetes management, thyroid function tests can help assess thyroid disease, and histopathological examination can provide information essential to cancer diagnosis.

The World Health Organization's Laboratory Quality Management System Handbook explains that laboratories must manage multiple interconnected processes to support the accuracy, reliability and timeliness of their results.

The WHO framework considers the entire testing pathway—from selecting and requesting the appropriate test to specimen collection, examination, reporting and interpretation.

This has an important consequence for patients.

Even when an analyser performs technically as intended, errors elsewhere in the testing pathway can affect the usefulness of the final report.

A specimen may be incorrectly identified, mishandled during transportation, exposed to unsuitable conditions, or associated with an incorrect transcription of results.

A good laboratory therefore needs more than well-maintained instruments. It needs a system that manages quality throughout the testing process.

Scientific reference: World Health Organization. Laboratory Quality Management System: Handbook. 2011. WHO publication.

Our Experience: Why Accreditation Matters Beyond a Certificate

From the experience of the laboratory director, Dr. Bhasin's Lab

Our experience with NABL accreditation began in 2008, when our laboratory received its first accreditation.

But our commitment to laboratory quality did not begin with the certificate.

Before accreditation, we were already practising equipment calibration, internal quality control and external quality assessment as part of our own laboratory discipline.

Accreditation gave these practices a more structured framework and subjected our processes to independent technical evaluation.

For us, this was one of the most important developments in laboratory quality management.

Instead of relying solely on our own assessment of whether our systems were appropriate, we became part of a process in which our competence and quality systems could be examined against internationally recognised requirements.

Accreditation also brought continuing responsibilities for staff competence, procedural consistency, documentation and independent assessment.

Our experience has taught us that accreditation is formal recognition of competence. Quality itself is something a laboratory must work to maintain every day.

The distinction is important. A certificate is evidence of an assessment process—not a substitute for daily professional responsibility.

The Three Stages of Laboratory Testing: Where Errors Can Occur

The WHO laboratory quality framework describes three broad stages of testing:

1. Pre-analytical: Before examination

This stage includes patient identification, test requests, sample collection, labelling, transportation, storage and sample acceptance.

2. Analytical: During examination

This involves the examination method, instruments, reagents, personnel, quality-control processes and generation of analytical results.

3. Post-analytical: After examination

This stage includes result review, report authorisation, communication and the handling of relevant findings.

All three stages contribute to laboratory quality.

What does European research tell us about errors before testing?

A 2019 study associated with the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for the Preanalytical Phase examined how European laboratories monitored errors occurring before analysis.

The survey received 1,405 valid responses from 37 countries.

Among its findings, 94% of the relevant respondents reported monitoring preanalytical errors, but approaches to documentation, evaluation and corrective action varied considerably between laboratories.

The researchers emphasised that the preanalytical stage remains particularly vulnerable because many activities occur outside the laboratory and involve different healthcare personnel and systems.

Potential problems include patient or specimen misidentification, inappropriate storage or transportation, haemolysis and sample contamination.

The study demonstrated that simply identifying an error is not enough. Laboratories also need processes for evaluating findings and responding to quality problems.

What this means for patients: The way your sample is identified, collected, transported and accepted can be just as important as the analytical process itself.

Scientific reference: European survey on preanalytical sample handling — Part 1: How do European laboratories monitor the preanalytical phase? Biochemia Medica. 2019;29(2):020704. Read the peer-reviewed study.

A Real Example from Our Laboratory: Detecting a Contaminated Batch of Viral Transport Medium

During the COVID-19 pandemic, our laboratory was involved in molecular testing using specimens collected in viral transport medium (VTM).

VTM is used for the collection and transport of appropriate specimens for respiratory viral testing, including some molecular assays.

Many patients naturally assume that laboratory quality control begins only when the collected specimen reaches the RT-PCR instrument.

In reality, the materials used to collect and transport samples also require appropriate quality safeguards.

As part of our laboratory process, incoming batches of VTM were checked before being released for routine use.

During the pandemic, one batch received from a manufacturer was identified as contaminated during these checks.

Because the batch was examined before use, it was withheld from routine patient testing.

This incident reinforced a principle we consider fundamental:

Quality management is not confined to the analyser. It begins with the materials and processes involved before a patient's specimen is tested.

Depending on the type of contamination, unsuitable collection media can compromise molecular testing and potentially contribute to misleading findings.

Detecting such problems before clinical use helps reduce avoidable testing risks.

The incident illustrates why laboratories must assess the suitability of consumables and materials in accordance with their testing methods and quality procedures.

Laboratory case note: This incident is based on the laboratory director's first-hand recollection. The original batch verification and nonconformity records should be checked before publication to document the type of contamination, investigative findings and corrective action.

Internal Quality Control, External Quality Assessment and Proficiency Testing: What Is the Difference?

Quality control is central to laboratory medicine, but it is not one single activity.

The World Health Organization's Manual for Organizing a National External Quality Assessment Programme for Health Laboratories and Other Testing Sites explains that quality management requires complementary activities involving internal process control, proficiency testing and continuing improvement.

Understanding these distinctions helps patients appreciate what happens behind a laboratory report.

Internal Quality Control (IQC)

Internal quality control involves procedures performed within the laboratory to monitor the performance of examination systems.

For many quantitative tests, laboratories analyse control materials with defined or expected performance characteristics.

Control results are evaluated against established acceptance criteria.

Multilevel controls can help monitor analytical performance at different concentrations.

Statistical approaches, including appropriate Westgard quality-control rules, can help laboratories recognise potentially unacceptable analytical variation.

At Dr. Bhasin's Lab, we place strong emphasis on multilevel internal quality control for applicable quantitative examinations.

A result produced by an instrument should not be treated as dependable merely because the instrument displays a number.

The laboratory must have appropriate evidence that its examination system is performing acceptably.

External Quality Assessment (EQA)

External quality assessment provides a mechanism for evaluating laboratory performance using samples, exercises or assessment processes organised outside the laboratory.

Where applicable, a laboratory may receive material from an external provider, perform the specified examination and submit its results for evaluation.

The findings can help identify potential performance problems and opportunities for improvement.

Proficiency Testing (PT)

Proficiency testing is a particular form of external assessment in which participants are evaluated against established criteria through organised interlaboratory comparisons.

It provides an additional means of evaluating technical performance.

However, participation alone does not establish that every patient result is correct. Laboratories must assess their performance, investigate unacceptable findings and take appropriate action.

Why are all these systems necessary?

Internal quality control monitors performance within the laboratory. External assessment provides an additional perspective on the laboratory's performance. Quality improvement addresses problems identified through these and other processes.

They are complementary rather than interchangeable.

Scientific reference: World Health Organization. Manual for Organizing a National External Quality Assessment Programme for Health Laboratories and Other Testing Sites. 2016. WHO manual.

How Do Experts Measure Laboratory Errors and Patient Safety?

Laboratory quality is sometimes presented in vague promotional terms such as accuracy, precision, reliability and excellence.

But laboratory professionals need measurable indicators to understand how well processes are functioning.

The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Working Group on Laboratory Errors and Patient Safety has proposed an internationally applicable panel of essential quality indicators.

Its recommendations identify six groups of indicators covering the entire testing process.

These include:

1. Misidentified test requests and samples

Monitoring situations in which patient requests or specimens are incorrectly identified.

2. Sample rejection rates

Tracking specimens that cannot be accepted for examination because they do not meet defined criteria.

3. Haemolysis rates

Monitoring samples affected by red-cell breakdown, which can interfere with some laboratory measurements.

4. Unacceptable external quality assessment results

Tracking analytical performance that fails to meet established EQA or proficiency testing criteria.

5. Cardiac troponin turnaround times

Monitoring clinically important reporting intervals for troponin testing in emergency-care settings.

6. Incorrect or corrected laboratory reports

Monitoring reporting errors identified after results have been issued.

These indicators illustrate an important principle.

The quality of a laboratory is not adequately assessed by looking at analytical accuracy alone.

Patient identification, sample suitability, analytical performance, timely reporting and reporting accuracy all matter.

The IFCC recommendations provide a useful international framework for measuring and comparing laboratory performance.

Not every indicator is applicable to every laboratory service. For example, emergency-department troponin turnaround-time indicators depend on the relevant service being offered.

Scientific reference: IFCC Working Group on Laboratory Errors and Patient Safety. Recommendations for the Global Adoption of an Essential Quality Indicators Panel in Laboratory Medicine. Clinical Chemistry and Laboratory Medicine. DOI: 10.1515/cclm-2025-1462. Read the publication.

Three Quality Practices We Emphasise at Dr. Bhasin's Lab

Our approach to laboratory quality places particular emphasis on three areas.

Primary sample barcoding

Wherever appropriate and operationally feasible, we emphasise primary sample barcoding to link specimens with the relevant patient and laboratory request information.

This reduces reliance on repeated manual transcription and supports sample traceability.

However, barcoding must be combined with correct patient identification at the point of collection.

Analyser interfacing with the laboratory information system

Where analysers are electronically interfaced with the laboratory information system (LIS), barcodes can be used to associate specimens with test requests and transmit results back to the LIS.

This reduces opportunities for transcription errors associated with manual entry.

Appropriate interface validation, exception handling and professional verification remain necessary.

Risk-appropriate internal quality control

We emphasise defined quality-control procedures appropriate to the examination method.

For relevant quantitative tests, this includes multilevel controls and statistically based acceptance rules.

For qualitative tests and other examination methods, quality assurance may involve appropriate positive and negative controls, procedural checks or other validated arrangements.

The objective is not to apply identical controls to every test, but to use scientifically appropriate procedures that monitor the reliability of each testing system.

Together, these practices reflect our commitment to controlling errors before, during and after examination.

Why the Laboratory Doctor Matters More Than Patients May Realise

Patients often associate pathology laboratories with automated analysers and trained technicians.

Both are essential, but laboratory medicine requires professional oversight extending beyond the operation of instruments.

Pathologists, clinical biochemists, microbiologists and other appropriately qualified laboratory professionals contribute to laboratory quality through their expertise.

Their responsibilities may include selecting suitable examination methods, determining quality requirements, supervising technical activities, evaluating unexpected findings, reviewing laboratory processes and fulfilling their professional responsibilities for reporting and interpretation.

A laboratory report may contain accurate analytical measurements but still require careful review in its clinical and technical context.

At Dr. Bhasin's Lab, we regard medical oversight as an important part of laboratory practice.

We do not view the laboratory doctor's role as merely signing a completed report.

Our approach emphasises professional responsibility for the systems through which results are produced and evaluated.

As our laboratory director explains:

“It is not just the machine. It is the person behind the machine who matters.”

For patients, this is a reminder that laboratory quality depends on professional competence as well as technology.

How Much Do Laboratory Tests Influence Medical Decisions? Examining the Popular 70% Claim

You may have read that laboratory results influence approximately 70% of medical decisions.

This statement is frequently repeated in discussions about the importance of laboratory medicine.

However, the scientific evidence behind the precise percentage is less certain than the popularity of the claim suggests.

In a 2011 editorial published in Annals of Clinical Biochemistry, clinical biochemist Mike J. Hallworth examined the origins and evidence supporting the claim.

The review found that the frequently quoted percentage was based substantially on historical estimates, unpublished information and statements that had been repeatedly cited in different forms.

Hallworth argued that the contribution of laboratory medicine to healthcare is important, but that broad percentage claims require stronger evidence.

This distinction matters.

Laboratory tests undoubtedly contribute to numerous clinical decisions, including diagnosis, treatment selection and monitoring.

But their influence varies between specialties, clinical settings, illnesses and individual patients.

We believe the importance of laboratory medicine should be explained using defensible scientific evidence rather than repeating an attractive statistic without adequate support.

The same principle applies to laboratory accreditation: meaningful evidence is more valuable than exaggerated claims.

Scientific reference: Hallworth MJ. The ‘70% claim’: what is the evidence base? Annals of Clinical Biochemistry. 2011;48(6):487–488. DOI: 10.1258/acb.2011.011177. Read the editorial.

How Accreditation Supports Staff Training and a Culture of Quality

One of the important benefits of accreditation at Dr. Bhasin's Lab has been its influence on how our team approaches laboratory responsibilities.

Accreditation requires appropriate systems for training, competence, quality management and review.

From our experience, the benefits go beyond fulfilling documentary requirements.

Regular assessment encourages laboratory staff to understand the reasons behind their procedures.

It supports a culture in which phlebotomists, technicians, laboratory professionals and quality personnel recognise that every stage contributes to the final result.

External assessment also introduces independent scrutiny and opportunities for improvement.

We have found that the accreditation process helps reinforce staff ownership of their work and responsibility for following established practices.

This philosophy can be expressed simply:

“Quality means doing things correctly, even when nobody is watching.”

The objective is not merely to pass an audit. It is to make appropriate laboratory practices a normal part of everyday work.

Does NABL Accreditation Guarantee the Best Results?

No.

NABL accreditation provides independent recognition that a laboratory has demonstrated conformity with applicable accreditation requirements for its defined scope.

It does not guarantee that every test result will be free from error, nor does it establish that every accredited laboratory performs identically.

NABL's terms and conditions explicitly distinguish accreditation from a warranty or guarantee of laboratory results.

Patients should therefore view accreditation as an important quality indicator, alongside other factors such as professional competence, appropriate sample collection, communication and suitability for the required examination.

NABL Accreditation and International Recognition: Understanding ILAC and APAC

NABL is part of international accreditation recognition arrangements involving organisations such as the International Laboratory Accreditation Cooperation (ILAC) and Asia Pacific Accreditation Cooperation (APAC).

A Mutual Recognition Arrangement, or MRA, supports confidence between participating accreditation bodies through established peer-evaluation systems.

These arrangements can facilitate acceptance of results generated by laboratories accredited for the relevant activities.

Global Accreditation Cooperation Incorporated (Global ACI) was established in January 2026 to bring together the work of ILAC and the International Accreditation Forum.

For patients, the significance lies in the internationally established framework for assessing laboratory competence.

However, MRA participation does not mean that every medical report is automatically accepted by every hospital, insurer, embassy, immigration authority or healthcare organisation overseas.

Individual acceptance depends on the receiving organisation's requirements and the relevant accredited scope.

Reference: NABL. International Recognition of Accreditation. Official NABL explanation.

Is NABL Accreditation Compulsory for Pathology Laboratories in India?

NABL accreditation is generally voluntary except where accreditation is specifically mandated under an applicable requirement.

Accreditation and statutory regulation are separate matters.

India has legislation and other regulatory requirements affecting clinical establishments and medical laboratory practice, with differences in implementation between jurisdictions.

NABL accreditation does not replace applicable legal obligations.

For patients, its value is that it offers an independently verifiable assessment of a laboratory's quality management arrangements and technical competence within an approved scope.

How Can You Verify Whether a Laboratory Is NABL Accredited?

Before selecting a pathology laboratory, patients can:

Check the laboratory's NABL accreditation certificate.

Verify the accredited location and validity dates.

Review its approved Scope of Accreditation.

Confirm whether the required examination is covered.

Check the laboratory's information on the official NABL website.

A laboratory offering a test is not necessarily accredited for that specific examination.

Understanding this distinction helps patients make more informed decisions.

NABL Accreditation at Dr. Bhasin's Lab, Greater Kailash, New Delhi

Dr. Bhasin's Lab holds NABL accreditation against ISO 15189:2022 for its accredited medical testing facility in Greater Kailash Part 1, New Delhi.

Our accreditation details

The official Scope of Accreditation specifies the examinations and methods recognised under NABL accreditation.

The laboratory's accredited scope includes specified activities within Clinical Biochemistry, Clinical Pathology, Histopathology, Cytopathology and Molecular Diagnostics.

Patients and referring doctors should refer to the current scope to confirm whether a particular examination is included.

View our NABL Accreditation Certificate

View our Scope of Accreditation

Verify our Accreditation on the NABL Website

The document links will be activated after connecting the verified source files.

Frequently Asked Questions About NABL Accreditation

What is the full form of NABL?

NABL stands for National Accreditation Board for Testing and Calibration Laboratories.

Why is NABL accreditation important for blood tests?

It provides independent recognition of a laboratory's technical competence and quality management arrangements for specified testing activities. This helps patients evaluate laboratories beyond price or advertising claims.

Does NABL accreditation ensure 100% accurate reports?

No. NABL accreditation is not a guarantee of error-free reports. It demonstrates that the laboratory has been independently assessed against relevant quality and competence requirements.

Is quality control only about checking laboratory machines?

No. Quality management addresses preanalytical, analytical and postanalytical processes, including patient identification, sample collection, examination and reporting.

What is the difference between IQC and EQA?

Internal quality control monitors testing performance within a laboratory. External quality assessment evaluates aspects of laboratory performance through externally organised assessment processes.

What is ISO 15189:2022?

ISO 15189:2022 is an international standard defining requirements for quality and competence in medical laboratories.

Does NABL accreditation apply to every test offered by a pathology laboratory?

No. Accreditation applies only to the examinations and activities included in the laboratory's current approved scope.

Are NABL-accredited reports accepted internationally?

International mutual recognition arrangements support recognition of accredited laboratory activities. Acceptance of individual medical reports depends on the requirements of the receiving organisation.

Are all pathology laboratories legally required to obtain NABL accreditation?

NABL accreditation is generally voluntary, except where required under an applicable regulation, programme or other binding condition. Laboratories must independently comply with all relevant statutory obligations.

How do I verify NABL accreditation in Delhi?

Check the laboratory's official certificate and scope, and confirm the details through NABL's published accreditation information.

Our Approach: Clinical Responsibility, Personal Attention

A laboratory report is more than a set of numbers.

Behind every result is a sequence of decisions, technical processes and professional responsibilities.

At Dr. Bhasin's Lab, our experience has reinforced the importance of combining recognised quality standards with continuous supervision, training and attention to detail.

NABL accreditation provides an independently assessed framework for demonstrating competence.

Our responsibility is to maintain appropriate quality practices in the laboratory every day.

Clinical Responsibility. Personal Attention.

This article is intended for medical education and does not replace the advice of a qualified treating clinician.

Scientific References

International Organization for Standardization. ISO 15189:2022: Medical laboratories — Requirements for quality and competence. ISO.

World Health Organization. Laboratory Quality Management System: Handbook. 2011. WHO.

World Health Organization. Manual for Organizing a National External Quality Assessment Programme for Health Laboratories and Other Testing Sites. 2016. WHO.

European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase. European survey on preanalytical sample handling — Part 1. Biochemia Medica. 2019;29(2):020704. Full text.

IFCC Working Group on Laboratory Errors and Patient Safety. Recommendations for the Global Adoption of an Essential Quality Indicators Panel in Laboratory Medicine. Clinical Chemistry and Laboratory Medicine. DOI: 10.1515/cclm-2025-1462. PubMed.

Hallworth MJ. The ‘70% claim’: what is the evidence base? Annals of Clinical Biochemistry. 2011;48(6):487–488. Original article.

National Accreditation Board for Testing and Calibration Laboratories. NABL 100A: General Information Brochure. August 2026 amendment.

National Accreditation Board for Testing and Calibration Laboratories. NABL 131: Terms and Conditions for Obtaining and Maintaining NABL Accreditation. January 2026 amendment.

NABL. International Recognition of Accreditation. Official NABL website.