Molecular Tools in Diagnosis: Revolutionizing Disease Detection
Updated on:June 18, 2025
Abstract
The field of diagnostics has undergone a transformative revolution with the advent of molecular tools. These advanced molecular techniques have revolutionized the landscape of disease diagnosis, offering unprecedented accuracy, speed, and specificity compared to conventional methods. This article explores a diverse array of techniques that analyse biomolecules such as nucleic acids, proteins, and metabolites at the molecular level. These tools provide clinicians and researchers with invaluable insights into the underlying molecular mechanisms of diseases, enables early detection and helps in designing strategies for personalized treatment.
Introduction
Molecular diagnosis refers to the use of molecular biology techniques to identify and characterize disease-related biomarkers at the molecular level. This approach enables more accurate, sensitive, and specific detection of diseases compared to traditional methods. Molecular diagnostic tools encompass a wide range of techniques and technologies used to analyse nucleic acids (DNA and RNA) and proteins at the molecular level. Here are some key molecular diagnostic tools:
Polymerase Chain Reaction (PCR): PCR is a fundamental molecular biology technique that has revolutionized diagnostics. It is a technique which is used to amplify specific DNA sequences and thereby allows for the exponential amplification of a target DNA region which enables the detection of even small amounts of DNA. PCR enables the rapid and sensitive detection of pathogens, including viruses, bacteria, fungi, and parasites, by amplifying their specific nucleic acid sequences. This is invaluable in diagnosing infectious diseases such as HIV, hepatitis, influenza, COVID-19, and many others.
Next-Generation Sequencing (NGS): NGS technologies allow for high-throughput sequencing of DNA or RNA molecules. NGS enables the simultaneous sequencing of large regions of the genome, providing a detailed view of an individual's genetic composition. It is instrumental in the diagnosis of inherited genetic disorders by identifying pathogenic variants responsible for conditions such as cystic fibrosis, muscular dystrophy, and Huntington's disease. NGS plays a pivotal role in cancer diagnosis, prognosis, and treatment decision-making where tumor profiling information guides personalized treatment strategies, including targeted therapies, immunotherapies. NGS-based approaches, such as non-invasive prenatal testing (NIPT) and preimplantation genetic testing (PGT), provide non-invasive and highly sensitive methods for detecting fetal chromosomal abnormalities, single gene disorders, and inherited conditions during pregnancy.
Microarrays: Microarray technology offers powerful diagnostic capabilities by enabling comprehensive analysis of genetic, epigenetic, and proteomic signatures associated with various diseases and conditions. Microarrays are extensively used to analyse the expression levels of thousands of genes at a same time that enables researchers and clinicians to study gene expression patterns associated with various diseases, such as cancer subtypes, autoimmune disorders, and neurodegenerative diseases. Also, microbial microarrays enable the rapid and high-throughput identification of pathogenic strains, antimicrobial resistance genes, and virulence factors in clinical samples, aiding in the diagnosis and management of infectious diseases and outbreak surveillance.
Fluorescence In Situ Hybridization (FISH): FISH is a cytogenetic technique that involves hybridization of fluorescently labelled DNA probes to complementary target sequences that will help in detecting and localizing specific DNA sequences within cells or tissues. FISH is extensively employed in oncology for the diagnosis and classification of various cancers. FISH is also utilized in prenatal testing for the rapid detection of chromosomal abnormalities in fetal cells collected via procedures like amniocentesis or chorionic villus sampling (CVS). Common applications include the diagnosis of trisomies (e.g., trisomy 21, 18, 13), sex chromosome anomalies (e.g., Klinefelter syndrome, Turner syndrome) and chromosomal deletions or duplications associated with genetic disorders.
CRISPR-based Diagnostics: CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) technology shows great potential in diagnostics by providing rapid, sensitive, and specific detection methods for pathogens, genetic mutations. CRISPR-based diagnostics can rapidly and accurately detect the presence of pathogens, including viruses, bacteria, fungi, and parasites, in clinical samples. CRISPR technology can be utilized to detect specific genetic mutations associated with inherited disorders, cancer, and other diseases. Multiplexed CRISPR-based assays can simultaneously detect and differentiate between multiple pathogens or genetic variants within a single sample. CRISPR-based diagnostic tools, like SHERLOCK (Specific High-sensitivity Enzymatic Reporter UnLOCKing) and DETECTR (DNA Endonuclease-Targeted CRISPR Trans Reporter), facilitate rapid and sensitive detection of pathogens, genetic mutations, and other molecular targets.
Lateral Flow Assays: Lateral flow assays are rapid and portable diagnostic tests that utilize antibodies or nucleic acid probes to detect specific targets in clinical samples. They are commonly used for point-of-care testing of infectious diseases caused by bacteria, viruses, and parasites, pregnancy testing, and detection of biomarkers.
Conclusion
In conclusion, these molecular diagnostic tools serve a vital role in healthcare aiding diagnosis of disease, predicting outcomes, selection of treatment and monitoring patient response to therapy. They continue to advance rapidly, driving innovation in the field of molecular diagnostics and personalized medicine.
Written By:
Dr. Swati Singh
Department of Medical Laboratory Technology & Biochemistry
Assistant Professor
