Features

PCR and eccentric genius who invented it

Published

6 years ago

2021/01/12

By Prof Kirthi Tennakone
(Email: ktenna@yahoo.co.uk )

Hardly a day passes without the letters, PCR, – the acronym for polymerase chain reaction — being mentioned. To most of us PCR sounds just a test for knowing whether someone has contracted COVID-19 or not.

The polymerase chain reaction is a game changing technique offering diverse and far reaching applications beyond a gold standard for COVID-19 detection.

It is fascinating and entertaining to learn about polymerase chain reaction and its discoverer Kary Mullis, nicknamed untamed genius.

The invention of PCR is intimately connected to our understanding of the cause of biological inheritance. The reason why we have features resembling our parents. A mystery that lead to the discovery of DNA and development of the science of life thereafter. Brief digression into this subject helps to fathom what PCR really means.

Understanding the cause of biological

inheritance and discovery of DNA

Humans have wondered why progeny resemble parents and have some physical and mental traits of the latter. A sprout from a minuscule banyan seed always grows into a gigantus of the same kind but never a tender mustard plant. The ancient Greeks believed that a creature to be born or a plant to germinate subsisted inside the sperm and the seed respectively in their miniature forms. A different idea gained ground later and lasted for more than 2,000 years that physical traits acquired by parents indirectly pass to the offspring. A proponent of this hypothesis in recent times was the French naturalist Lamarck. If Lamarckism were true, amputation of the tails of successive offspring of mice would eventually lead to a generation of tailless rodents. All such experiments failed.

Lamarckism did not confront creationism and intelligent design to the hurt religious establishment. It attracted communists as a way of improving the society to meet ideological aspirations and enhance crop production. The infamous agronomist Lysenko mistrusting proven science attempted to reform Soviet agriculture believing Lamarckian ideals. He probably faked experimental results to justify his thesis and advised famers to abandon use of fertilizers and grow of each crop intensely segregated in order to increase the yield. The result was a famine that starved millions – a good lesson for those who advocate pseudoscience promoting quackeries as remedies for COVID-19 or recommend withdrawal of fertilizer on basis of unreliable claims.

When the world was deluded by Lamarckism, definitive clues as to what really causes inheritance followed from the seminal works two revolutionaries, Charles Darwin and Gregor Mendel.

Darwin in his presentation of the theory of evolution noted that the decedents of a given species, sometimes include one’s with distinct variations in their characteristics, referred to as mutants. If the new qualities acquired by the mutants fits the environment, they survived and continuation of evolution via natural selection led to the emergence of new species.

Another question crucial to understand the cause of inheritance has been how the traits of male and female sexual partners were represented in the offspring? Without resorting to experiment and careful analysis, the conservative stream of biologists continued to believe it should be a blend of the maternal and paternal traits. In late 1890s, the work of the Austrian monk Gregor Mendel, a mathematician and a botanist as well, provided a conflicting answer. In an experiment lasting for eight years Mendel planted different strains peas, cross-pollinated them and germinated the seeds brought forth to see features of the of linage such as the height to which they grew and the colour of flowers. His results did not indicate blending of traits, instead the original attributes appeared in each generation with different probabilities. Crossing tall and dwarf varieties never procreated medium size plants; instead, they were either tall or dwarf. Mendel concluded that traits were passed to the progeny as distinct qualities – what we refer to as genes today.

The work of Darwin and Mendel compounded by subsequent findings, pinpointed the inescapable conclusion that a chemical substance transmitted inheritance. Many believed it should be a protein. In 1942, the prescient Austrian physicist Erwin Schrodinger, famous for the quantum theory, expressed an alternative opinion. He hypothesized that the heredity determining entity, needed to be a molecule capable of encoding information and replication. Aroused by Schrodinger’s proposition, chemists all over the world competitively researched to identify the causative agent. In early 1950s, American biologist Watson and British physicist Crick, showed that the genetic material found in cells of animals and plants was deoxyribonucleic acid DNA – a lengthy molecule constituted basically of two strands of four different repeated subunits. Molecules of DNA encode information using these units as a four letter alphabet.

Cells of every organism contain DNA characteristic to the species and unique to each individual. The order in which millions of these units sequentially are arranged in a helical chain, is analogous to an instruction manual detailing the development of the organism. Short sequences of the four units in the chain represent genes, dictating special instructions, just like a sentence or a paragraph in the manual.

Polymerase chain reaction (PCR) and its uses

PCR is a technique of amplifying million-fold a tiny quantity of DNA representing a sequence of interest in minutes so that it could be detected even in minutest quantities – justifying the use of the term chain reaction with polymerase as the catalyst ensuing the reaction. In the analogy of DNA to an instruction manual, PCR would be like inserting a book mark to fix a certain page and copying that page many times.

In finest detail DNA is unique to each individual, whether it is a human or a bacterium. The difference between DNAs of individuals in a given species is minuscule. Yet, the identity of a person can be established from DNA in the smear of saliva over a stamp by PCR. Again just like finding a needle in a hay stack, minute quantities of a specific type of DNA in a sample containing excessive quantities of DNAs from background sources, can be selectively ascertained by running a PCR. The technique finds wide range of applications in medical diagnostics, forensics and criminology, archaeology and paleontology, phylogenetics, cloning, gene editing etc.

How is PCR detecting corona virus?

The genetic material of the corona virus is RNA – a single strand of DNA. The test first converts RNA into DNA making it double stranded and then selectively amplify a fragment of DNA covering a specific sequence using special reagents. The amplification enables detection by a screening system. Test is extremely sensitive; in fact, too sensitive, responding to even the dead fragments of the virus.

The impact of PCR on forensics and criminology is unprecedented. The technique has enabled not only identification of criminals but also the exoneration of innocent. A man on death row for eight years has been released and compensated as PCR became available.

Kary Mullis: The man who discovered PCR

Kary Mullis born in Southern United States 1944 was exceptional and radical. As a high schooler he meddled with chemicals at home and created an ingenious technique for making rocket fuels. His homemade rockets propelled miles into the sky frightening pilots maneuvering airplanes to land. Having earned a bachelor’s degree in chemistry from Georgia Institute of Technology he moved to University of California, Berkeley to pursue studies towards a doctoral degree in chemistry. A fashionable field of study at that time was chemistry of DNA or molecular biology. Instead of following courses in biochemistry needed for the thesis, he opted for astrophysics, saying he could learn the former discipline talking to colleagues. He wrote an article on a fundamental problem in astrophysics and succeeded getting it printed in the prestigious journal Nature. He was a surfing enthusiast and guitarist.

At the oral examination for qualifying to register as a doctoral candidate, Mullis was found to be unprepared and weak in conventional biochemistry. However, his paper on an astrophysical subject rather than biochemistry saved him from disqualification. The committee decided despite odd behaviour and unpreparedness, the man was talented and granted him approval for registration. Mullis earned a Ph.D. in 1973 and decided to give up research to become a writer and worked in a restaurant. Later, one of his friends persuaded him to a job in a biochemical company, at least to earn a living. There, he worked in a laboratory devoted to DNA chemistry, often quarrelling with coworkers. In early 1980s, he came up with the idea of PCR, but no one took him seriously. The paper he wrote was rejected twice and finally published in a less acclaimed journal. Soon the world acknowledged the utmost significance of his work and Mullis shared 1993 chemistry Nobel Prize. He resorted to eccentric behaviour criticizing the establishment and mainstream thinking, earning reputation as the untamed genius. When he was invited to a high-standing conference on molecular biology, he projected three slides of female nudes, lambasted the way of funding research and vanished! In an interview, Mullis has said Nobel Prize serves as a licence to do things unacceptable.

Kary Mullis, who passed away in 2019, will be remembered as a demarcater of biology into two epochs – before PCR and after PCR. Fortunately, the pandemic is post – PCR. Otherwise the situation would have taken a more deadly and devastating turn.

The invention of PCR stands as a prime example to highlight how fundamental studies motivating creativity, foresight and hard work can pay off unexpectedly. A constant reminder to research and academic institutions to retain this spirit of accommodating the most talented and not the mediocre who entertain trivialities for the shake of survival. The latter even amend (adulterate) the established mandates for fostering advanced studies to suit them. And deceiving the policymaker and general public, stating the amendments (adulterations) were affected to meet national interest (self-interest).

Would a man of the calibre of Kary Mullis be considered for employment or allowed to continue in our institutions? Will a committee here act with the same altruism and consideration as the one that endorsed the candidature of Kary Mullis?

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Features

Sections of US media looking power straight in the eye

Published

22 hours ago

2026/10/1

Sahan Weerasooriya

President Trump addressing the media at the White House.(BBC)

Some fundamental freedoms seen to be at the heart of democracy in the US – religion, speech, the press, assembly and the right to petition the government – are at risk of being undermined at present by the country’s Executive President. However, the latter is being legally challenged on this score by some sections of the US media and the citizenry of the country could take heart from this notable defense of media freedom.

In fact this is good news for the world of democracy. The push back is coming from organizations such as CNN, ABC, CBS, Fox, NBC who constitute the nucleus as it were of the US media and their solidarity no less than their resourcefulness calls for commendation.

Following a recent White House decision to suspend CNN from what was referred to as ‘participation in presidential pool coverages’, the other media organizations mentioned refused to replace it in the pool. Their position was that the public had a right to receive ‘accurate and independent information about the government.’

Earlier, the White House decided to bar MS NOW and Politico from entering its premises following the restrictions imposed on CNN. The organizations were accused of publishing “FAKE NEWS’ , ‘Fiction’ and ‘lies’ in respect of the administration. These organizations lost no time in initiating a federal lawsuit accusing the central administration of violating their rights guaranteed by the First Amendment.

However, the latter litigating organizations could now consider themselves as having been vindicated because the federal court hearing their case has ordered the Trump administration to temporarily restore White House press access to journalists from the mentioned media institutions. Notably, the court has declared that the ban is ‘likely unconstitutional’. The case is proceeding.

The mass media of the most vibrant democracies of the West ought to be no strangers to such inspirational acts of solidarity and exemplifications of independence but there are lessons here for the democracies of the South that could stand them in good stead. Minus the right of a people to be informed, the rest of fundamental rights featuring in Southern Bills of Rights and legislation of the kind are bereft of substance and meaning.

It is informed decision-making on the part of a citizenry that makes for democratic vibrancy and on this score many a Southern democracy fails. While Southern publics generally demand of their governments continuous economic well being and substantive material benefits they are not equally desirous of being informed and knowledgeable.

This lacuna in the consciousness of many Southern publics enables their governments ‘to get off the hook’, so to speak and govern, or more often misgovern, their countries with impunity. Among other factors, this species of mass ignorance makes it possible for governments to dismantle democracy and rule in perpetuity.

Accordingly, an educated and constantly informed public is an essential precondition for the flourishing of democracy and independent media are integral to this process. Minus an independent mass media sector that meets the knowledge needs of the people responsibly, democracy is as good as dead.

Needless to say, those sections of the US media that are currently taking the Trump administration to task over its media curbs are acutely aware of the cruciality of these fundamental knowledge requirements.

The hope of democratic opinion worldwide and locally is likely to be that media independence would thrive in the manner in which it is flourishing in the most vibrant and accountable democracies of the West.

Southern countries such as Sri Lanka that lay claim to democratic credentials, but are democracy-deficient in many ways, need to be particularly cognizant of these requirements. The publics of these countries need to go the extra mile to ensure the thriving of an independent but responsible mass media sector.

In fact it is veritably a matter of life and death. It is only an independent media sector that could, while ensuring the existence of an informed public, impress on the latter the need to protect and perpetuate its fundamental rights. In the absence of these campaigns, such publics could be eventually having on their hands governments that boast of ruling in perpetuity.

Taking a leaf from the sections of the US media referred to independent media organizations in Southern states need to act in solidarity as well. They would need to act on the basis of the principle that acts of victimization suffered by members in their fold at the hands of governments, for instance, are in fact inimical acts directed at their collectivity and which call for united remedial action. In short, no independent mass media institution could see itself as ‘an island’.

Besides some general guidance on the importance of media independence and solidarity, the message coming from the US with regard to media praxis is that power must be stood-up to unblinkingly. The mentioned sections of the US media are primarily in a struggle to ward off encroachments on their independence in the areas of policy and practice by the political executive, that is the President.

The latter would ride rough-shod over the media in the absence of robust opposition by the media itself to inimical executive action of this kind.

While media independence needs to be seen as crucial to democratic development, an obligation is cast on the media to ensure that it uses such independence responsibly and constructively.

The worst that could afflict a media sector is for it to fall prey to the clichetic ‘freedom of the wild ass’. In fact recurring irresponsibility on the part of the media could lend credence to the perception that a tightly regulated media is best for a country. It is a short step from this misguided view to the position that political authoritarianism is best for a state. That turn of events would be of course catastrophic for a democracy.

The issues discussed thus far point to the need for a broad discourse among Southern democracies in particular on what is best for them in this connection. Given the risks underscored earlier for Southern countries in particular a broad discussion on the matters at hand, which includes the public, emerges as a must for Sri Lanka. Besides, media solidarity within democratic countries and internationally is a must.

Features

What lessons can be learned to improve quality of Sri Lanka’s Grade 6 syllabus

Published

22 hours ago

2026/10/1

Sahan Weerasooriya

Prime Minister Dr. Harini Amarasuriya

by Prof. M. W. Amarasiri de Silva

Following public controversy over an inappropriate web link found in an English study module, the Sri Lankan government formally deferred the full rollout of the Grade 6 curriculum reforms to January 2027. In the interim, state schools will maintain the existing syllabus, reverting to standard eight-period daily timetables and previous textbooks to ensure uninterrupted instruction. Prime Minister and Minister of Education Dr. Harini Amarasuriya emphasized that this temporary pause allows the Education Ministry to thoroughly review all instructional materials, fix editorial flaws, and conduct scientific impact assessments across pilot schools prior to nation-wide implementation.

To address the oversight, an expert committee evaluated the flawed materials, completed necessary amendments, and finalised discussions to resubmit corrected modules for printing. Beyond revising written texts, the Ministry established a broader preparation roadmap—allocating funds for extensive teacher training programs set to begin mid-year, alongside scheduled informational briefings for parents, teachers, and students. Prime Minister Amarasuriya reaffirmed that none of the valid first-term modules were completely discarded or scrapped, preserving state resources while systematically rebuilding public trust and strengthening quality assurance protocols.

In this respect, this article reviews the current grade 6 syllabus comparing it with similar syllabi of India and the USA, with a view to make recommendations for the upcoming grade 6 syllabus revision.

Architecture of nation’s future

Education is the quiet architecture of a nation’s future. It is the unseen scaffolding upon which generations build their character, their intellect, and their capacity to contribute meaningfully to society. In Sri Lanka, the Grade 6 syllabus occupies a particularly important place in this architecture. It is the bridge between primary learning and the more demanding intellectual terrain of secondary education. It is the moment when children begin to move from learning basic facts to understanding concepts, from memorising information to applying knowledge, and from passive reception to active engagement. Yet, despite its importance, the Grade 6 curriculum in Sri Lanka has long struggled with issues of breadth, depth, relevance, and pedagogy. As global education systems evolve, Sri Lanka must examine what lessons can be learned from international models—particularly India and the United States—to strengthen its own curriculum and prepare students for a rapidly changing world.

The first lesson Sri Lanka can learn is the value of conceptual clarity. India’s NCERT curriculum, especially in Mathematics and Science, is globally respected for its logical progression and conceptual depth. Indian students are introduced early to the idea that mathematics is not merely a set of procedures but a language of reasoning. They learn why a ratio works, not just how to compute one. They understand the structure of an equation, not merely the steps to solve it. In Science, they explore the properties of materials, the structure of plants, and the principles of motion with a clarity that encourages curiosity rather than rote memorisation.

Sri Lanka’s Grade 6 syllabus, while competency-based, often leans heavily toward content coverage. Students are expected to learn many topics, but the time allocated for each is limited, and the teaching culture often emphasizes memorisation over understanding. If Sri Lanka wishes to improve the quality of its syllabus, it must embrace the idea that fewer topics taught well are better than many topics taught superficially. Conceptual mastery builds confidence, and confidence builds lifelong learners.

Lesson from the US

A second lesson comes from the United States, where the curriculum is built around skills rather than content. American students in Grade 6 are expected to read complex texts, analyse arguments, write essays supported by evidence, conduct experiments, and engage in collaborative projects. The emphasis is not on how much they know but on what they can do with what they know. This skills-based approach encourages critical thinking, creativity, and independence—qualities essential for success in the modern world.

Sri Lanka’s syllabus, by contrast, often rewards students for reproducing information rather than interpreting it. The exam culture reinforces this tendency, as students are assessed primarily through written tests that measure recall. To improve the syllabus, Sri Lanka must integrate more opportunities for students to think, question, debate, and create. The classroom should become a space where students learn to solve problems, not just memorize solutions.

Another important lesson comes from the breadth of Sri Lanka’s own curriculum. One of the strengths of the Sri Lankan system is its inclusion of cultural and religious education. Subjects such as Buddhism, Hinduism, Islam, and Christianity provide moral grounding and cultural identity. Art, Music, Drama, and Health contribute to holistic development. These subjects remind students that education is not merely about academic achievement but about becoming a balanced human being. However, breadth without depth can become burdensome. Grade 6 students in Sri Lanka often juggle more than ten subjects, each with its own textbook, competencies, and assessments. This creates pressure not only for students but also for teachers, who must rush through content to meet syllabus requirements. The lesson here is not to reduce cultural subjects but to integrate them more meaningfully. Religious education can be taught through ethical discussions, community projects, and reflective writing. Art and Music can be connected to history, literature, and social studies. Health can be linked to science and physical education. Integration reduces overload while enriching learning.

Another lesson from India

India offers another valuable lesson in the form of standardised textbooks. NCERT books are used across the country, ensuring consistency in quality and content. They are written by subject experts, reviewed rigorously, and updated periodically. Sri Lanka’s textbooks, while generally well-structured, vary in quality and often lag behind modern pedagogical standards. Some are dense, text-heavy, and lacking in visual aids or real-world examples. To improve the syllabus, Sri Lanka must invest in high-quality textbooks that are engaging, accessible, and aligned with contemporary educational research. Textbooks should not merely transmit information; they should inspire curiosity. They should include stories, diagrams, experiments, and activities that make learning enjoyable and meaningful.

The United States provides a lesson in inquiry-based science education. American students conduct experiments, build models, observe natural phenomena, and engage in engineering design challenges. They learn science not as a set of facts but as a process of discovery. Sri Lanka’s science curriculum includes experiments, but many schools lack the resources, laboratory facilities, or teacher training to implement them effectively. Improving the syllabus requires improving the ecosystem around it. Schools need laboratories, equipment, and teacher development programs that empower educators to teach science through inquiry. A syllabus is only as strong as the environment in which it is taught. ***

International models

Another area where Sri Lanka can learn from international models is language education. In India, students often learn three languages—English, Hindi, and Sanskrit or Urdu. This heavy language load has its challenges, but it also produces students with strong linguistic skills. In the United States, English Language Arts emphasises reading complex texts, writing arguments, and analysing literature. Sri Lanka’s English curriculum, while improving, still struggles with uneven implementation across schools. Many students reach secondary school without adequate proficiency in English, limiting their access to global knowledge. To improve the syllabus, Sri Lanka must strengthen English instruction through better teacher training, more reading opportunities, and a shift from grammar-heavy teaching to communication-focused learning. At the same time, Sinhala and Tamil instruction should be modernised to include creative writing, literature appreciation, and critical reading.

Social Studies is another area ripe for improvement. Sri Lanka’s curriculum includes History, Geography, and Civics, but the teaching often emphasises memorization of dates, definitions, and facts. India’s Social Science curriculum, while also content-heavy, provides clearer conceptual frameworks. The United States, however, excels in teaching civics and citizenship. American students learn how governments function, how laws are made, how communities solve problems, and how citizens participate in democracy. Sri Lanka can strengthen its Civics curriculum by incorporating more discussions on governance, rights, responsibilities, and community engagement. Students should learn not only the structure of government but also the values that sustain it—justice, equality, and participation.

One of the most important lessons Sri Lanka can learn is the value of reducing exam pressure. In both India and Sri Lanka, exams dominate the educational landscape. Students are judged primarily by their ability to perform on written tests. The United States, while not free from assessment challenges, uses a wider range of evaluation methods—projects, presentations, portfolios, and continuous assessment. These methods allow students to demonstrate learning in diverse ways. Sri Lanka should consider adopting a more balanced assessment system that values creativity, collaboration, and practical skills alongside academic knowledge.

Technology integration is another area where Sri Lanka can improve. The United States incorporates digital literacy, coding, online research, and digital citizenship into the curriculum. Sri Lanka’s ICT syllabus is well-structured, but implementation varies widely. Many schools lack computers, internet access, or trained ICT teachers. Improving the syllabus requires improving infrastructure. Students must learn to navigate the digital world safely and effectively. They must learn coding not as a luxury but as a basic skill. They must learn to evaluate online information critically, a skill essential in an era of misinformation.

Teacher training

Teacher training is perhaps the most critical lesson of all. A syllabus is only as effective as the teachers who deliver it. India invests heavily in teacher training through national programs, workshops, and online platforms. The United States emphasises professional development, peer collaboration, and instructional coaching. Sri Lanka must strengthen its teacher training programmes, ensuring that educators understand not only what to teach but how to teach it. Teachers should be trained in inquiry-based learning, differentiated instruction, formative assessment, and classroom management. They should be empowered to adapt the syllabus to the needs of their students rather than follow it mechanically.

Sri Lanka must learn the lesson of relevance. A syllabus must prepare students not only for exams but for life. It must teach them how to think, how to communicate, how to solve problems, and how to work with others. It must prepare them for a world where knowledge is abundant, but wisdom is scarce. It must help them navigate a future shaped by technology, globalisation, environmental challenges, and social change. To improve the syllabus, Sri Lanka must ask: What kind of citizens do we want to produce? What kind of thinkers? What kind of leaders? The answers to these questions should shape the curriculum.

Lastly, improving the quality of Sri Lanka’s Grade 6 syllabus requires learning from both international models and local strengths. From India, Sri Lanka can learn the value of conceptual clarity and standardised textbooks. From the United States, it can learn the importance of skills, inquiry, and creativity. From its own traditions, it can preserve cultural education, moral development, and holistic learning. The goal is not to copy another country’s system but to build a uniquely Sri Lankan curriculum that is modern, relevant, and empowering. A curriculum that honours the past while preparing students for the future. A curriculum that nurtures thinkers, creators, and compassionate citizens. A curriculum worthy of a nation with immense potential and a proud educational heritage. If Sri Lanka embraces these lessons, the Grade 6 syllabus can become not just a bridge to secondary education but a foundation for national progress.

Features

Three magical nights at Colombo Fashion Week

Published

22 hours ago

2026/10/1

Sahan Weerasooriya

Melloney Dassanayaka is certainly a familiar name here, and abroad, as well, having represented Sri Lanka at the Miss Universe 2024 pageant, held in Mexico.

A former National Basketball player, she is also involved in several projects, beneficial to the community, including financial literacy for single women-headed families in the country.

A banker by profession, Melloney hold a Bachelor’s Degree in Business Administration.

Melloney with Asanka de Mel of Lovi Sri Lanka

This extremely talented old girl of Holy Family Convent, Bambalapitiya, was in the limelight, once more, when she was seen on the ramp at Colombo Fashion Week.

It was her very first experience, at this prestigious event, and she loved every minute of it, she said, and, what’s more, she was featured on three consecutive days.

According to the itinerary, on day 01 she walked for Lovi Sri Lanka; day 02 Rizwan Beyg (Pakistan designer), Arsath Furkhan (Indian designer), Haoyi Yan (Chinese designer) and Samant Chauhan (Indian designer); and on day 03 Vaishali Shandangule (Indian designer).