The silent revolution that transformed diagnosis and research in Chile
Imagine being able to detect diseases with precision a thousand times greater than traditional methods, identifying genetic predispositions before symptoms appear, or personalizing treatments according to each patient's genetic code. This is not science fiction but the result of the incorporation of molecular biology techniques into modern medicine.
In Chile, this revolution has been uniquely documented through the pages of the Revista Médica de Chile, which for decades has served as a thermometer of the evolution of national scientific research. A revealing study published in 2000 quantified for the first time how these techniques had progressively integrated into national medical research, marking a turning point in Chilean science 4 .
Molecular biology is the scientific discipline concerned with the study of biomolecules and processes that define life at the molecular level, focusing especially on DNA, RNA, and proteins 1 . These techniques allow researchers to identify, sequence, modify, and express genes, opening possibilities that seemed unthinkable decades ago in disease diagnosis and treatment 3 .
"The specific detection and quantification of genetic material in a biological sample has shown a significant impact in all health areas, especially in infectious diseases and cancer" 9 .
The impact on medicine has been so profound that today it is difficult to imagine specialties such as oncology, infectology, or medical genetics without these tools.
The seminal study published in the Revista Médica de Chile in 2000 compared two periods separated by a decade: 1987-1989 versus 1997-1999 4 . Researchers meticulously reviewed all research articles, clinical experiences, and case reports published during these periods, identifying which used molecular biology techniques according to a predefined list that included everything from PCR and DNA sequencing to ELISA and Western Blot 4 .
The findings showed a remarkable transformation in just ten years. While in the 1987-1989 period only 16.7% of articles used molecular biology techniques, in the 1997-1999 period this figure had risen to 28.6% – a statistically significant increase that demonstrated the growing incorporation of these tools into national medical research 4 .
| Period | Total Articles | Articles Using MB Techniques | Percentage |
|---|---|---|---|
| 1987-1989 | 341 | 57 | 16.7% |
| 1997-1999 | 318 | 91 | 28.6% |
In the first analyzed period (1987-1989), the landscape was dominated by techniques such as radioimmunoassay (RIA), immunofluorescence, and protein electrophoresis 4 . These represented the most advanced available in Chilean laboratories at the time but were far from the revolution to come.
The second period (1997-1999) showed a dramatic change. Techniques such as ELISA and Western Blot more than tripled their use, but what was truly transformative was the appearance of techniques like polymerase chain reaction (PCR), Southern Blot, electroimmunoassay, DNA cutting with restriction enzymes, and DNA sequencing 4 .
| Technique | 1987-1989 | 1997-1999 |
|---|---|---|
| RIA | Dominant | Decreased |
| Immunofluorescence | Dominant | Decreased |
| Protein Electrophoresis | Dominant | Maintained |
| ELISA | Uncommon | Tripled |
| Western Blot | Uncommon | Tripled |
| PCR | Didn't exist | Appeared |
| DNA Sequencing | Didn't exist | Appeared |
Essential equipment for PCR technique that allows programmed temperature cycles to amplify DNA.
Molecular scissors that cut DNA at specific sequences, fundamental for genetic analysis 9 .
Labeled nucleic acid fragments that allow identifying complementary sequences through hybridization 9 .
Porous medium for separating DNA or RNA fragments by size through electrophoresis 3 .
Plasmids or other vehicles that allow inserting genes of interest for study or expression 3 .
The story behind the development of PCR is as extraordinary as the technique itself. Biochemist Kary B. Mullis conceived the idea during a road trip one Friday night, as he would recall in his Nobel Prize in Chemistry speech in 1993: "One friday night I was driving... My girlfriend, Jennifer Barnett, was asleep. I was thinking. Since oligonucleotides were not that hard to make anymore, wouldn't it be simple enough to put two of them into the reaction..." 9 .
Heat DNA to 94-96°C to separate the two strands.
Lower temperature to 50-65°C to allow primers to bind to target sequences.
Adjust to 72°C for DNA polymerase to synthesize new DNA strands.
Perform 25-40 cycles of these steps, doubling the target DNA in each cycle 9 .
The power of PCR lies in its ability for exponential amplification. Starting with a single DNA molecule, after 30 cycles more than 1 billion copies can be obtained – enough to visualize, analyze, or use in diagnostics.
| Cycle Number | Number of Copies |
|---|---|
| 1 | 2 |
| 10 | 1,024 |
| 20 | 1,048,576 |
| 30 | 1,073,741,824 |
| 40 | 1,099,511,627,776 |
The adoption of molecular techniques was not uniform across all medical specialties. The study revealed that in the second analyzed period, certain specialties led this revolution 4 :
These differences reflect how different specialties benefited variably from molecular tools, with those related to infectious diseases, genetic disorders, and complex conditions at the forefront of technological adoption.
If PCR represented the first revolution in molecular biology, techniques like CRISPR-Cas9 are driving the next transformative wave 3 . This gene editing technology allows modifying DNA sequences with unprecedented precision, opening possibilities for gene therapies that previously belonged to the realm of speculation.
The molecular diagnostics field continues its expansion, with sustained growth of over 12% annually globally, expected to reach a market of over US$60 billion 9 .
In Chile, this trend has been maintained, with a progressive incorporation of these tools not only in university research but also in routine clinical practice.
The journey documented in the pages of the Revista Médica de Chile tells a story of scientific progress, adaptability, and technological growth. From those first techniques of immunofluorescence and RIA to the sophistication of PCR and genomic sequencing, Chilean medical research has demonstrated a remarkable ability to incorporate the molecular tools that define modern medicine.
"Molecular biology techniques have been incorporated rapidly and progressively as research tools in biomedicine and clinical medicine in Chile" 4 .
This trend, far from stopping, has accelerated in the new millennium, promising even more exciting advances in the diagnosis and treatment of diseases affecting the Chilean population.
The molecular revolution in Chilean medicine, meticulously measured through its scientific publications, demonstrates that the country has been not only a witness but an active participant in one of the most significant transformations of contemporary medical science.