What is molecular testing?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 7, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Molecular testing is a diagnostic method that analyzes genetic material (DNA or RNA) or proteins to detect specific changes associated with diseases, and it is defined as procedures designed to detect somatic or germline mutations in DNA and changes in gene or protein expression that could impact the diagnosis, prognosis, prediction, and evaluation of therapy of patients with cancer 1.

Key Aspects of Molecular Testing

  • It involves examining the molecular structure of cells to identify mutations, abnormalities, or the presence of pathogens.
  • These tests can detect infectious agents like viruses and bacteria, identify genetic disorders, guide cancer treatment decisions, and monitor disease progression.
  • Common molecular testing techniques include polymerase chain reaction (PCR), next-generation sequencing, fluorescence in situ hybridization (FISH), and microarrays.
  • Molecular testing provides more precise information than traditional diagnostic methods because it examines the fundamental biological processes underlying diseases, allowing for earlier detection, more accurate diagnosis, personalized treatment approaches, and better monitoring of treatment effectiveness 1.

Importance of Molecular Testing

  • The field continues to advance rapidly, making tests more accessible, affordable, and comprehensive for various medical applications.
  • Molecular testing is crucial for identifying predictive biomarkers, which are essential for personalized therapy and ensuring that cancer patients receive reliable molecular test results to determine their eligibility for treatment with specific drugs that target altered molecular pathways 1.

Recent Developments

  • The Infectious Diseases Society of America guidelines on the diagnosis of COVID-19 highlight the benefits and harms of molecular diagnostic testing, emphasizing the importance of rapid testing for making management decisions related to treatment and isolation 1.
  • The European Consensus Conference for External Quality Assessment in Molecular Pathology emphasizes the need for ensuring the quality of molecular testing to provide reliable results for personalized therapy 1.

From the Research

Definition of Molecular Testing

Molecular testing refers to the use of genetic technologies to detect changes in an individual's genes or chromosomes. This type of testing is used to diagnose genetic disorders, predict disease risk, and guide treatment decisions.

Types of Molecular Testing

  • Single-gene testing: used to detect changes in a specific gene associated with a particular disorder 2
  • Gene panel testing: used to detect changes in multiple genes associated with a particular disorder or group of disorders 3
  • Exome sequencing: used to detect changes in all of the protein-coding genes in an individual's genome 3
  • Genome sequencing: used to detect changes in an individual's entire genome 3

Applications of Molecular Testing

  • Diagnosis of genetic disorders: molecular testing can be used to diagnose genetic disorders, such as Mendelian disorders 3
  • Predicting disease risk: molecular testing can be used to predict an individual's risk of developing certain diseases, such as cancer 4
  • Guiding treatment decisions: molecular testing can be used to guide treatment decisions, such as identifying individuals who may benefit from targeted therapies 4

Challenges and Limitations

  • Interpretation of test results: molecular testing can generate large amounts of data, which can be challenging to interpret 5, 6
  • Limited access to next-generation sequencing: in some regions, access to next-generation sequencing technologies may be limited, making it difficult to implement molecular testing 5
  • Need for genetic counseling: molecular testing can have significant implications for individuals and families, highlighting the need for genetic counseling and support 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Overview of molecular genetic diagnosis.

Current protocols in human genetics, 2013

Research

Genetic testing.

Hematology/oncology clinics of North America, 2000

Research

An Overview of Molecular Genetic Diagnosis Techniques.

Current protocols in human genetics, 2020

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.