“Molecular medicine is a field of science that applies the knowledge of molecular biology to medicine for disease diagnosis, prognosis, and treatment.”
Last week, on 7th March 2025, I was invited to present a topic, “molecular medicine,” to the college students. I have years of experience working in molecular diagnosis with a routine job to study gene, DNA or chromosomal-level alterations associated with a disease.
So, I was already familiar with the topic and have a strong understanding of how techniques like PCR, sequencing, and NGS are used in diagnosis.
Teaching is a great responsibility. Although I have worked with these techniques, I began researching the topic further and was shocked to find that crucial information on this important subject is scarce.
Google is showing the results of only journals and University courses. So, I decided to write an article on this. And here it is!
Learn the concept of molecular medicine, its applications, techniques used and courses related information in this article.
Stay tuned.
Related article: Why Microbial Genetics Is The Future of Microbiology? Comparison and Applications.
Key Topics:
What is Molecular Medicine?
First, let us understand the terminology. The phrase is made up of two separate words from two different fields: Molecular + Medicine.
‘Molecular’ in the present context means ‘molecule or biological/cell molecule.’ Whereas ‘Medicine’ means ‘related to medicine or medical.’
Nucleic acid- DNA or RNA, protein, carbohydrates, etc. are known as biological or cellular molecules. Medical or medicine includes diagnosing, treating and managing a disease (in general).
So molecular medicine is related to, we can say, testing or studying biological molecules- DNA, RNA or protein to diagnose, treat or manage a disease.
Make sense? Let’s move further.
Molecular medicine is an advanced field of medical science dealing with understanding diseases at the molecular or cellular level. It applies the knowledge of genetics, biochemistry or biotechnology to understand,
- How disease originates.
- How it can be diagnosed.
- How it progresses.
- How to treat and manage it, if applicable.
Traditional medicine practice focuses on the symptoms associated with a disease. First, the doctor counsels the patient, asking what health-related problems and difficulties they are facing.
Based on those observations and their experience, they suggest medication, surgery or other treatment options. Conversely, molecular medicine allows us to investigate the root cause of the disease.
It helps to uderstand which underlying mechanism, cellular pathway, cell activity and molecule is involved in causing a disease? Testing helps identify the relevant molecules or issues and can even quantify them to assess disease severity.
Now, this approach is groundbreaking and has revolutionized the whole medical field.
A cell is a basic unit of life. It contains DNA as a genetic materia. Various cellular pathways avail proper cell functioning. And these cellular pathways are made by the interaction between molecules.
DNA, RNA, protein and carbohydrates are molecules of life. DNA is a genetic material that has the function to store, express and inherit information to consecutive generations.
Genes- the functional part of the DNA, synthesize different proteins. These proteins participate in various cellular activities and pathways. Disruption in any pathway or activity causes a disease.
This means that if a gene can’t produce the correct protein, the protein-associated cellular activity is affected and results in a disease. For instance, a mutation in the BRCA1 or 2 gene fails to perform DNA repair and results in breast cancer.
By studying the molecule itself, the disease’s root cause can be investigated. It will help to provide better personalized medicine or treatment.
Various techniques are available to study either nucleic acid or protein directly for disease risk assessment, diagnosis, prognosis, treatment and management.
Definition
“Molecular medicine is an interdisciplinary field that applies the knowledge of cell and molecular biology, genetics, and biotechnology to understand, diagnose, and treat diseases at a molecular level.”
Molecular Medicine Techniques
The list of molecular medicine techniques that doctors advise is given in the image above.
In our previous article on the role of genetic technologies in medicine, I already explained all the genetic techniques in detail. Here, I am just giving you a brief overview.
PCR and related variants (qPCR, RT-PCR and digital PCR) are used in molecular biology to amplify and quantify the nucleic acid, enabling doctors to detect genetic mutations associated with a disease or cancer and infection.
It has a very high diagnostic value. The quantitative and real-time PCR is frequently used in clinical diagnosis to determine infection from any biological sample.
The DNA sequencing technique- Sanger sequencing has been valued as a gold-standard method in molecular medicine. It can investigate sequence-level alterations associated with a disease or cancer.
For instance, mutations in the case of the BRCA1 or BRCA2 gene are directly involved in causing breast cancer. Sanger sequencing can reveal those mutations. It is extensively used in clinical diagnosis. It is also employed as a validation tool in gene therapy.
The massive parallel sequencing platform NGS (Next-generation sequencing) allows genome-wide analysis. Variants associated with a disease or cancer from the entire genome can be investigated.
NGS has been employed in molecular medicine for disease risk assessment, diagnosis, prognosis, screening, treatment and personalized medicines.
FISH- Fluorescence In Situ Hybridization can detect DNA mutations associated with a disease or cancer from the chromosome. It is a hybridization-based technique widely used in cancer studies, diagnosis, prognosis and screening.
Gene expression microarray analyzes gene expression from thousands of genes and detects mutations associated with complex conditions and diseases. The present technique is extensively instrumental in cancer studies.
The same technique used for DNA is also used for RNA analysis. Techniques like northern blot, RNA sequencing, reverse transcription PCR, single cell RNA sequencing, microRNA profiling, etc., have been extensively used for gene expression and cancer study in molecular medicine.
Western blotting, ELISA, Immunohistochemistry (IHC), Immunofluorescence (IF), Mass spectroscopy (MS), protein microarray, Surface plasmon resonance (SPR), 2D- gel and chromatin immunoprecipitation (ChIP) are techniques used for protein studies and detection in molecular medicine.
However, nucleic acid detection techniques give more power as they directly deal with a protein coding gene.
| Molecular medicine technique | Applications |
| PCR | Detects genetic mutations, infections, and hereditary diseases. |
| qPCR | Quantifies gene expression and viral load in real-time. |
| RT-PCR | Detects RNA viruses like SARS-CoV-2 and monitors gene expression. |
| Sanger sequencing | Identifies point mutations in genetic disorders and cancer. |
| NGS | Enables whole-genome/exome sequencing for precision medicine. |
| FISH | Detects chromosomal abnormalities like translocations in cancer. |
| DNA microarray | Analyzes gene expression patterns for disease diagnostics. |
| RNA sequencing | Studies transcriptomic changes in diseases and treatments. |
Applications of Molecular Medicine
In the field of medicine, molecular medicine techniques have been instrumental from the very beginning- disease risk assessment to the final step, that is to determine the treatment outcomes.
Explore the role of molecular medicine during each step.
Disease risk assessment
Molecular medicine plays a significant role in disease predisposition. Genetic screening can determine a person’s risk for a disease or cancer. For instance, in the case of hereditary breast cancer testing, women at a higher risk of breast and ovarian cancer can be identified.
In addition, it can also estimate the risk for other family members for getting the breast cancer mutation. Techniques like NGS can investigate genome-wide genetic alterations, link those variants with diseases and estimate the likelihood of getting a cancer or disease.
Disease risk assessment also helps in surgical decision-making. For instance, BRCA gene testing allows doctors to make a decision on whether to go for a mastectomy or not.
Molecular medicine in diagnosis:
Molecular medicine revolutionized the entire diagnostic field by accurately identifying a disease at a genetic or molecular level. It has been employed for inherited genetic diseases, studying complex conditions and cancer.
High throughput techniques like NGS or gene expression microarray identify disease-causing variants and study gene expression, respectively.
In addition, genetic markers are also studied to diagnose cancer. Liquid biopsy, such as cell-free tumor DNA studies, reveal if the cancer is metastasizing or not.
The PCR-based method allows rapid quantification of infection-causing pathogens (bacteria or viruses). Such methods are fast, accurate and safe to use. Hundreds of PCR-based pathogen screening kits are now available for use in diagnosis.
Molecular medicine is further used in prenatal genetic diagnosis by early detection of disease or disease-causing genetic markers or variants. This particularly helps in prevention and taking preventive measures.
Medical surgeries:
Molecular medicine plays a crucial role in surgical decision-making. Traditional medicine was based on symptomatic analysis and lacked quantitative assessment. However, molecular medicine provides marker-based quantitative data.
This particularly helps in determining whether the surgery is necessary. Best surgical approach and post-surgical care options.
For instance, studying the breast cancer genetic markers helps doctors to know if the mastectomy is required or sufficient. After surgery, the liquid biopsy determines the risk of tumor progression.
This helps doctors to better opt for the surgery, post-surgical prognosis and effective treatment options.
Interestingly, HLA typing is a type of molecular medicine technique required before organ transplantation. Organ transplantation compatibility has been determined for the likelihood of graft acceptance or rejection. HLA typing has been the gold-standard technique too, to do so.
HLA is a human leukocyte antigen that regulates the immune response and it varies among individuals. A mismatched HLA profile can trigger immune rejection. HLA typing has been instrumental in vital organ transplants such as kidney, liver or heart.
Here, the HLA genetic markers between donor and recipients have been matched to establish transplantation competency. HLA typing is the most trusted and accurate molecular medicine marker right now.
Moreover, it is also used for stem cell and bone marrow therapy and platelet transfusion. Poor HLA match causes adverse immune conditions like graft versus host disease (GVHD). Such conditions are lethal for patients.
Treatment and personalized medicine:
Molecular medicine is also a valuable tool for disease treatment and personalized medicines. Treatment plans and medications can be advised based on the tumor profile of the patient in cancer.
Gene expression studies allow us to investigate tumor aggressiveness and are useful for designing the treatment and dosage for the patient. In addition, by looking at the genetic makeup of the patient, the treatment or medication can also be personalized.
This personalized medicine prevents side effects and improves the effectiveness of the treatment. For instance, HER2-positive breast cancer patients receive targeted trastuzumab therapy after surgery, which minimizes the risk of cancer recurrence.
In another example, during surgery, pharmacogenomic testing helps decide on anesthesia dose and pain management based on the individual’s genetic makeup.
Techniques like NGS and DNA microarray-based pharmacogenomic testing revolutionized treatment and patient care by availing personalized medicine
Monitoring treatment outcomes
It is crucial to monitor treatment or surgical outcomes. Liquid biopsy, post-surgery solid tissue biopsy or dd-cfDNA are instrumental in monitoring not only treatment but also surgical outcomes.
Liquid biopsy-based testing like cell-free tumor DNA analysis or gene expression from tissue biopsy is an important procedure to determine if the treatment, personalized medication or surgery is performed well or not.
A donor-derived cell-free DNA test determines graft rejection risk before symptoms appear; this helps in early intervention.
Infection tracking
Patients may get infections commonly as they have to visit the hospital regularly for diagnosis and treatment. Infection poses additional challenges by interfering with online treatment.
In addition, pre- or post-surgical infection is also commonly observed and creates serious problems after surgery. To avoid any unwanted infection risk, techniques like quantitative PCR are used to track the infection at different stages of the patient treatment.
It is now frequently used for post-surgery infection tracking. It is a fast, easy, safe and efficient technique.
Gene Therapy as molecular medicine
Gene therapy is a technique used to repair or replace the faulty gene causing disease. In this process, using either viral or non-viral vectors, a DNA sequence has been introduced into the host cell.
Techniques like CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Sequence) are a novel gene therapy approach to treat diseases. Two common components in this technique are the CRISPR sequence and the cas9 protein.
The guided RNA is designed to be complementary to the target gene. Cas9 guides the gRNA to the target site and performs a sequence-specific cut. Afterwards, the faulty part can be deleted or a new DNA sequence can be introduced here.
CRISPR-based gene therapies are more effective. For instance, the CRISPR-cas9 treatment for Duchenne Muscular Dystrophy can correct the mutation in the dystrophin gene. This reduces the severity of muscle degeneration.
Gene therapies are safer, less extensive, and non-invasive in comparison to medical surgery. We already wrote a complete series on this topic, you can explore it here.
Molecular medicine courses:
Many degree courses are now offered in this interdisciplinary field of molecular medicine. Such courses help students to understand molecular techniques and their applications in medicine.
Molecular medicine offers new opportunities to students to explore career options in the field of medicine or applied medicine.
While doing research for my guest lecture and writing this article, I also prepared an online course on molecular medicine. Our online course comprises videos, live classes, notes, pdfs and quizzes on molecular medicine.
The one-on-one interaction with experts will help students to get industry insights and career guidance in this field. Enroll in the molecular medicine course now.
Wrapping up:
Molecular medicine is the most emerging field, now! It applies the knowledge of cell and molecular biology to medical science, which the traditional medicine field lacked previously.
In recent times, doctors rely more on the molecular medicine test results for patient treatment, medication and surgery than any other techniques.
In the field of cancer, techniques like NGS and microarray provide additional benefits as such techniques are powerful enough to study the entire genome.
I hope you like this article. Do subscribe to Genetic Education and also check out our online course on molecular medicine.
