SPR (Surface Plasmon Resonance) technology

SPR (Surface Plasmon Resonance) technology

May 23, 2020 | Technology

SPR (Surface Plasmon Resonance) technology is a powerful and versatile analytical technique used to study molecular interactions in real-time. It is widely employed in various scientific fields, including biochemistry, biophysics, pharmaceutical research, and environmental monitoring. SPR technology provides valuable insights into the kinetics, affinity, and specificity of biomolecular interactions, offering a deeper understanding of complex biological processes and aiding in drug development and diagnostics.

Working Principle:
SPR is based on the principle of the excitation of surface plasmons, which are collective oscillations of free electrons that occur at the interface between a thin metal film (usually gold or silver) and a dielectric medium (typically glass or prism). When polarized light, such as laser light, is directed onto the metal surface at a specific angle known as the resonance angle, surface plasmons are excited, leading to a decrease in reflected light intensity.

When molecules bind to the metal surface, the local refractive index changes, altering the resonance condition and causing a shift in the angle of minimum light reflection. By monitoring this shift in real-time, researchers can quantitatively measure the interactions between molecules immobilized on the metal surface and those present in the surrounding solution.

Application in Biomedical Research:
SPR technology is widely used in the field of biomedical research to investigate a variety of biomolecular interactions. Some of the key applications include:

Protein-Protein Interactions: Researchers can study the binding interactions between proteins, determining their kinetics, affinities, and specificity. This information is crucial for understanding signaling pathways, enzymatic reactions, and protein-protein interactions in disease processes.

Protein-Ligand Interactions: SPR is valuable in drug discovery, as it allows the screening and characterization of potential drug candidates binding to target proteins. This aids in identifying molecules with high binding affinities, which may serve as leads for drug development.

Antibody-Antigen Interactions: SPR is used extensively in immunology to investigate antibody-antigen interactions, enabling the study of immune responses, antibody specificity, and the development of diagnostic assays.

DNA-Protein Interactions: SPR can be employed to examine the binding interactions between DNA and proteins, providing insights into transcription factor binding, DNA repair processes, and chromatin remodeling.

Advantages of SPR Technology:
SPR offers several advantages over traditional methods for studying molecular interactions:

Real-Time Analysis: SPR provides real-time, label-free measurements of molecular interactions, eliminating the need for fluorescent or radioactive labeling of molecules.

High Sensitivity: SPR can detect minute changes in molecular interactions, allowing for the study of weakly interacting or low-concentration molecules.

No Requirement for Conformational Changes: Unlike other techniques, SPR does not require conformational changes in molecules for detection, enabling the study of molecules in their native state.

Quantitative Analysis: SPR provides quantitative data on binding kinetics (association and dissociation rates) and equilibrium dissociation constants (KD), facilitating precise characterization of interactions.

Conclusion:
Surface Plasmon Resonance (SPR) technology has emerged as a powerful tool for studying molecular interactions in real-time. Its wide-ranging applications in biomedical research, drug development, and diagnostics have significantly contributed to our understanding of complex biological processes. By offering label-free, real-time, and quantitative data, SPR technology continues to be a valuable asset in unraveling the intricacies of molecular interactions and advancing scientific knowledge across various disciplines.

Molecular biology

Molecular biology

May 18, 2020 | Science, Technology

Molecular biology is a discipline that has revolutionised our understanding of life at the most fundamental level. By investigating the interactions and processes that occur within biological molecules, molecular biologists have unveiled the intricate mechanisms governing the structure, function, and regulation of cells. 

The field of molecular biology emerged in the mid-20th century as a multidisciplinary science that explores the biological phenomena at the molecular scale. It unites principles from genetics, biochemistry, and cell biology to decipher the blueprint of life encoded within the DNA, and how it directs the cell’s activities to maintain life and perpetuate genetic information. By investigating the interplay of biomolecules, molecular biologists have provided deep insights into the complex mechanisms that govern living organisms.

Historical Developments:

The historic foundation to molecular biology originated in the 1930s and 40s, making it a relatively new scientific field and arose from the convergence of work by geneticists, physicists, and structural chemists on a common problem: the nature of inheritance. Warren Weaver, director of the Division of Natural Sciences at the Rockefeller Foundation, coined the term “molecular biology” in 1938 in a report for the Foundation. Weaver and others encouraged research at the intersection of biology, chemistry and physics, while prominent physicists such as Niels Bohr and Erwin Schrödinger turned their attention to biology to explain the biochemical and biophysical basis of life. For Schroedinger, biology was to be reduced to the more fundamental principles of physics, while Max Delbrueck instead resisted such a reduction and sought what made biology unique. The former student of Thomas Morgan’s, Hermann J. Muller shift from Mendelian genetics to the study of gene structure raised  the question of the relation between the gene concepts found in those separate fields of genetics. And the import of experimental methods from physics to biology raised the question of the relation between those disciplines. Also, during the period between 1930s to 40s, other emerging cross-disciplinary fields such as colloid chemistry, biophysics and radiation biology, crystallography, have aided the development of molecular biology as a field of it’s own right. 

The formal foundations of molecular biology were laid with the discovery of the DNA double helix structure by Watson and Crick in 1953. This breakthrough unlocked the key to understanding how genetic information is stored and replicated. Subsequent advances in molecular biology, such as the elucidation of the genetic code and the discovery of DNA polymerases and RNA polymerases, paved the way for molecular genetics.

In the 1970s, the development of recombinant DNA technology, commonly known as genetic engineering, enabled scientists to manipulate and transfer genetic material between different organisms. This revolutionary technique has since had a profound impact on various fields, from agriculture to medicine.

The discoverers of the structure of DNA. James Watson (b.1928) at left and Francis Crick (b.1916), with their model of part of a DNA molecule in 1953. Crick and Watson met at the Cavendish Laboratory, Cambridge, in 1951. Their work on the structure of DNA was performed with a knowledge of Chargaff’s ratios of the bases in DNA and some access to the X-ray crystallography of Maurice Wilkins and Rosalind Franklin at King’s College London. Combining all of this work led to the deduction that DNA exists as a double helix. Crick, Watson and Wilkins shared the 1962 Nobel Prize for Physiology or Medicine, Franklin having died of cancer in 1958. Credit: A. Barrington Brown / Photo Researchers, Inc..

The Central Dogma of Molecular Biology: Decoding Life’s Blueprint

The Central Dogma of Molecular Biology is a foundational principle that underpins our understanding of the flow of genetic information within living organisms. Coined by Nobel laureate Francis Crick in 1958, the Central Dogma outlines the essential processes of DNA replication, transcription, and translation, shaping the way molecular biologists comprehend the intricacies of life. This essay delves into the significance ofthe Central Dogma, elucidating its core components and their crucial role in maintaining and propagating life.

The Central Dogma’s Components:

DNA Replication: DNA (deoxyribonucleic acid) is the hereditary material carrying genetic instructions that define an organism’s traits. Before cell division or reproduction, DNA must be faithfully copied to ensure the accurate transmission of genetic information to the next generation. DNA replication occurs during the cell cycle, involving the unwinding of the double helix and the synthesis of two identical daughter DNA strands, each complementary to one of the original parental strands.

Transcription: The process of transcription occurs in the cell nucleus, where the genetic information encoded in DNA is used to synthesize RNA (ribonucleic acid). RNA serves as a messenger, carrying the genetic code from the nucleus to the cytoplasm, where it participates in protein synthesis. During transcription, an enzyme called RNA polymerase reads the DNA template and synthesizes a complementary RNA strand, resulting in a messenger RNA (mRNA) molecule.

Translation: The final step of the Central Dogma is translation, which takes place in the cell’s cytoplasm. Translation involves converting the genetic code carried by mRNA into a functional protein. This process occurs at the ribosomes, where transfer RNA (tRNA) molecules bring specific amino acids to the ribosome based on the codons (three-nucleotide sequences) on the mRNA. The ribosome links these amino acids together, forming a polypeptide chain that folds into a functional protein.

The Significance of the Central Dogma: The Central Dogma represents a fundamental paradigm in molecular biology and serves as a guiding principle for understanding the molecular basis of life. It highlights the unidirectional flow of genetic information, with DNA acting as the stable repository of genetic instructions that is faithfully copied during cell division. This ensures the genetic continuity across generations, maintaining the genetic identity of organisms.

Additionally, the Central Dogma emphasizes the centrality of proteins as the key players in cellular functions. Proteins, synthesized through translation, carry out essential roles in catalyzing biochemical reactions, providing structural support, regulating gene expression, and facilitating communication within and between cells. Understanding the relationship between DNA, RNA, and proteins is vital for comprehending the molecular basis of diseases, cellular development, and evolutionary processes.

Expanding the Central Dogma: While the Central Dogma provided an initial framework for understanding genetic information, subsequent discoveries have expanded its scope. It has become evident that RNA can also play catalytic roles, acting as enzymes known as ribozymes. Moreover, some viruses can reverse the flow of genetic information through reverse transcription, converting RNA into DNA, challenging the strict unidirectionality originally described by the Central Dogma.

Key Concepts and Mechanisms:

Molecular biology investigates the essential biological processes, including DNA replication, transcription, and translation, that govern cellular activities. The central dogma of molecular biology, proposed by Francis Crick, describes the flow of genetic information from DNA to RNA to protein, with each step regulated by specific enzymes and factors.

The study of gene regulation is another crucial aspect of molecular biology. It involves the investigation of how cells control the expression of genes in response to internal and external signals. Understanding gene regulation has broad implications, as it underpins the development of multicellular organisms, cellular differentiation, and response to environmental cues.

Applications in Biotechnology:

The practical applications of molecular biology in biotechnology have been monumental. Genetic engineering has enabled the production of genetically modified organisms (GMOs) with enhanced traits, leading to increased crop yields, disease resistance, and improved nutritional content.

Additionally, the advent of molecular cloning techniques has facilitated the production of valuable therapeutic proteins, such as insulin and growth hormones, through the use of recombinant DNA technology. This has revolutionized medicine and led to the development of numerous biopharmaceuticals that have saved countless lives.

Medical Impact:

Molecular biology has transformed medical research and diagnosis. Techniques like the polymerase chain reaction (PCR) allow the amplification of specific DNA sequences, aiding in the detection of infectious agents, genetic disorders, and cancer markers. The identification of disease-causing mutations at the molecular level has empowered personalized medicine, enabling tailored treatments for individuals based on their genetic makeup.

Furthermore, advancements in genomics and proteomics have provided a deeper understanding of the genetic basis of diseases, leading to the discovery of potential therapeutic targets and the development of precision medicine approaches.

Conclusion:

Molecular biology has played a pivotal role in unlocking the secrets of life at the cellular level. Through the investigation of DNA, RNA, and proteins, molecular biologists have uncovered the mechanisms that govern biological processes and their regulation. This knowledge has not only broadened our understanding of life but also led to numerous practical applications in biotechnology and medicine. As technology continues to advance, molecular biology remains at the forefront of scientific discovery, promising a future of exciting breakthroughs and transformative impact on our society.

Who is a scientist?

Who is a scientist?

May 18, 2020 | Philosophy, Science

The term “scientist” is a relatively modern construct, born out of centuries of intellectual and philosophical evolution. The journey to define the identity of a scientist spans diverse historical contexts, reflecting the changing perceptions of knowledge, empirical inquiry, and the scientific method.

Ancient Philosophers and Natural Philosophers:

In the ancient world, the boundaries between what we now call science, philosophy, and natural philosophy (a precursor to science) were blurred. Philosophers like Aristotle and Pythagoras engaged in systematic inquiries into the natural world, seeking explanations for various phenomena. They laid the groundwork for empirical observation and rational thinking, but the pursuit of knowledge during this period was not confined to the realm of specialised scientists.

Medieval Scholars and the Emergence of Universities:

During the Middle Ages, the pursuit of knowledge shifted from individual philosophers to centers of learning known as universities. These institutions brought together scholars from diverse fields, including theology, philosophy, and the natural sciences. However, the distinction between what constituted a “scientist” and other scholars remained nebulous, with no specific designation for those dedicated solely to scientific pursuits.

The Scientific Revolution and the Rise of Modern Science:
The 16th and 17th centuries marked a transformative period known as the Scientific Revolution. Visionary figures like Nicolaus Copernicus, Galileo Galilei, Johannes Kepler, and Isaac Newton broke away from traditional dogma and embraced empirical experimentation and mathematical principles. The systematic application of the scientific method, along with the formulation of natural laws, heralded the emergence of modern science.

The Birth of the Term “Scientist”:

The term “scientist” itself was coined in the 19th century by Reverend William Whewell. He introduced it to distinguish those who pursued scientific inquiries from artists and philosophers. Previously, individuals conducting scientific investigations were referred to as “natural philosophers,” a term dating back to ancient times. The introduction of the term “scientist” marked a significant shift in how society perceived and classified those dedicated to the study of nature and the natural world.

Specialisation and Professionalisation of Science:

As scientific knowledge expanded and diversified, so did the number of scientific disciplines. The 19th and 20th centuries witnessed the professionalization of science, with researchers becoming increasingly specialized in their fields of study. The scientific community evolved, embracing rigorous education, peer-reviewed publications, and formal institutions dedicated to scientific research and education.

Contemporary Notions of a Scientist:

In the 21st century, the identity of a scientist is shaped by a combination of education, research, and engagement with society. Scientists are professionals with advanced degrees, working in academia, industry, government, or non-profit organizations. They are committed to the pursuit of empirical knowledge, employing the scientific method to answer questions and solve problems. Moreover, modern scientists are not only specialists in their fields but also collaborators across disciplines, recognizing the interconnectedness of scientific knowledge.

Conclusion:

The concept of a scientist has evolved significantly throughout history, from the natural philosophers of ancient times to the specialized professionals of today. The journey to define the identity of a scientist reflects the changing nature of human inquiry, intellectual pursuits, and societal values. As we continue to explore the natural world and unravel its mysteries, the role of the scientist remains pivotal, driving progress, innovation, and our collective understanding of the universe.

Can Science determine the objective truth?

Can Science determine the objective truth?

May 18, 2020 | Philosophy

Introduction:
The quest for objective truth has been a fundamental driving force behind scientific inquiry. Science, with its systematic approach, empirical evidence, and peer review process, aims to uncover universal principles that govern the natural world. However, the idea that science can fully and unerringly achieve objective truth is a topic of debate. This critical essay explores the strengths and limitations of science in determining objective truth, considering factors such as human biases, the nature of scientific paradigms, and the evolving nature of knowledge.

The Subjectivity of Observation and Interpretation:
Science relies heavily on observation and data collection, which, in turn, are inherently influenced by human perception and cognitive biases. Scientists are not immune to subjective perspectives, and the process of observation can be influenced by personal beliefs, cultural conditioning, or even unintentional biases. This subjectivity may affect how data is interpreted, leading to potential misinterpretations or selective reporting of results. Consequently, it becomes challenging to assert that scientific findings are entirely devoid of subjectivity and, therefore, represent objective truth.

The Influence of Scientific Paradigms:
Science operates within paradigms – accepted frameworks of knowledge that guide research and experimentation. Paradigms are essential for scientific progress, but they can also limit perspectives and shape how data is interpreted. When a prevailing paradigm dominates a field, dissenting views may be marginalized, hindering the consideration of alternative explanations or truths. The shift from classical mechanics to quantum mechanics is a prime example of how scientific paradigms have changed over time, leading to new and more comprehensive understandings of reality. This illustrates the dynamic nature of scientific truth and the limitations imposed by current paradigms.

The Falsifiability Criterion:
A critical aspect of science is the concept of falsifiability, proposed by philosopher Karl Popper. According to Popper, for a scientific theory to be valid, it must be testable and open to the possibility of being proven false through empirical observation. While this criterion enhances the rigor of scientific theories, it also raises questions about whether falsifiability can guarantee absolute objectivity. As scientific experiments are often conducted under specific conditions and may not account for all variables, there remains a level of uncertainty in drawing definitive conclusions.

Context Dependency and Evolving Knowledge:
Objective truth, by definition, should hold irrespective of context. However, scientific knowledge is continually evolving, with new discoveries challenging existing theories and paradigms. As our understanding of the universe expands, previously accepted scientific truths may be revised or even discarded. The process of revising knowledge is inherent in science, indicating that our understanding of objective truth is contingent upon our current level of comprehension. As a result, the pursuit of objective truth in science may be an ongoing, ever-changing endeavor.

Conclusion:
Science is a powerful tool for understanding the natural world and advancing human knowledge. It has revealed profound insights into the universe and provided solutions to numerous challenges. However, the claim that science can fully attain objective truth remains contentious. The inherent subjectivity in observation and interpretation, the influence of scientific paradigms, and the evolving nature of knowledge all contribute to the complexity of determining objective truth. Instead of striving for an absolute claim to truth, science’s strength lies in its ability to constantly refine and expand our understanding of the world, promoting critical thinking and empirical investigation. Acknowledging the limitations of science helps foster a more nuanced appreciation of the scientific method while encouraging a continuous search for deeper and more accurate explanations of reality.