Tag: Trends in Biotechnology

Science In Context

How a lawyer lost the case to a tree

Academia Plus

In 1993, in a murder trial in Arizona, a lawyer had an interesting remark- he said that he is probably the only lawyer to have lost the case to a tree!

Let us hear that story…

In 1992, on the outskirts of Phoenix, Arizona, a woman was found murdered. There was hardly any evidence left by the murderer. However, there is no such thing as a perfect crime. Read on to find out how forensic analysis led to justice.

At the crime scene, forensic investigators found a syringe, some pieces of clothing and a pager that did not belong to the victim (It’s an old case. Pagers were a thing back then, fellow millennials). Homicide detective Charlie Norton noticed fresh abrasion on a Palo verde tree at the crime spot, and took some bean pods off that particular tree.

A fingerprint search helped identify the victim as Denise Johnson. Denise was a single mother of two and lived in ‘the projects’.

The pager was traced to a truck driver Mark Bogan. When confronted, Bogan said that Denise had requested him for a ride and then tried to steal some things from him when he dropped her. He said that he took his wallet back from her but later noticed that his pager was missing.

Scratches on Bogan’s face did not escape the investigator’s eyes while they were interrogating him. However, no traces of blood or skin cells were found under Denise’s nails. Her autopsy revealed that she had died from ‘asphyxiation due to strangulation’.

When the investigator’s visited Bogan’s truck, there was no evidence to suggest that he was involved in the crime- no fingerprints, blood, or hair. However, in the back of the truck they found two bean pods from a Palo verde tree.

The only way to prove that Bogan was at the crime scene, was to prove that the pods in his truck came from that same tree. And that was tough, because obviously, there is not just one such tree there! Arizona has thousands of Palo verde trees.

Now, DNA forensics involving animals and humans is common place. But plants? Not at all. In 1980, Dr Alec Jeffreys developed the technique called genetic fingerprinting that was used as evidence to solve cases, but plant DNA analysis had never been admitted as evidence before.

This is where Dr Timothy Helentjaris came into the picture. A professor at the University of Arizona, Dr Timothy specialized in plant genetics. Since no one had extensively studied Palo verde trees before, Restriction Fragment Length Polymorphism (RFLP)- a DNA analysis technique used frequently for human DNA, could not be performed. Moreover, not enough DNA could be extracted. Hence Dr Helentjaris used the Randomly Amplified Polymorphic DNA (RAPD) technique which works despite low DNA concentration, on any biological sample.

In RAPD, the seeds are removed from the pods and ground to a fine powder. The DNA sample being too low to be analysed needs to be amplified by Polymerase Chain Reaction (PCR) which multiplies the DNA millions of times within a few hours. That sample is then run on an agarose electrophoresis gel and the gel is exposed to UV light to enable visualisation of DNA as short, horizontal bands. The band pattern for every individual is unique. This is the equivalent of a QR code, called a genetic fingerprint.

Dr Helentjaris found that the DNA band pattern of seeds from both pods in the truck, matched each other.  Furthermore, they also matched the DNA band pattern of the seeds from the pods that detective Norton had taken from the tree at the crime scene! When a similar analysis was carried out with DNA from other seed pods in the neighbourhood, there was no perfect match, proving their hunch right- about the pods in Bogan’s truck belonging to the tree at the crime scene.

The judge permitted the results of this DNA analysis to be submitted as evidence. Something that was unprecedented. The jury agreed that this piece of evidence wasn’t circumstantial and found Mark Bogan guilty of first degree murder, sentencing him to 25 year imprisonment.

And thus, despite having no obvious evidence of the victim, Bogan’s lawyer lost his case to the unique seed pods of the Palo verde tree!
Avani Jha Writer

Disclaimer: The content of this article is meant for educational and creative purposes only, and will not be directly used for generation of profits. All rights and responsibilities, including the authenticity of the information presented in this article belong to the original authors and their publications (listed below in the Bibliography section), and there is no copyright infringement intended.

Bibliography

Science In Context

Biosensors: a revolution in the healthcare sector

Academia Plus

Prognosis and diagnosis of any disease as well as its subsequent management has become quite easy now, with the advent in bioinstrumentation, more specifically with biosensors. Just as environmentalists can predict the level of pollution by analyzing the population of butterflies or the color of moths, a ‘biosensor’ is a device that detects our body’s physiological activity to send signals and analyze health-related conditions for diagnosis and/or subsequent treatment.

Everyone is rushing around in today’s fast world, and as a result of this daily pace, diseases are also becoming more prevalent. The lack of clinical resources has led to significant demand for wearable and portable healthcare devices as a potential solution.

Biosensors have become extremely popular today because they support the method of non-invasive monitoring – that is, a monitoring procedure that does not involve any surgical intervention in the body (Read more about the basics of biosensors).

These wearable sensors can be in the form of smartwatches, smart shoes, contact lenses, earpieces, and mouthpieces depending on the location of the body. The technology provides a wireless mechanism that makes it easier for patients to use. Skin is the outermost layer of our body and along with the protection, it also provides a lot of information about the physiological activity of the body through sweat and wound exudates. With the help of wristbands, patches, and smartwatches, the important details in case of hyperglycemia or hypertension can be measured to get instant treatment. Contact lenses can give information about changes in pH levels of the tears. Mouthpieces can be used to detect the rate of saliva production, which is known to be altered in response to exercise, stress, and dietary intake.

Today it might be difficult for people living in remote locations to have close access to any health center but devices such as these would help them get one step closer towards early detection and treatment.

Indeed, when it comes to biosensors, the future is already here. 
Nashrah Mubeen Writer

Disclaimer: The content of this article is meant for educational and creative purposes only, and will not be directly used for generation of profits. All rights and responsibilities, including the authenticity of the information presented in this article belong to the original authors and their publications (listed below in the Bibliography section), and there is no copyright infringement intended.

Bibliography

Science In Context

Synthetic Biology: the past, present & future

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The 21st Century is known as the era of technology and revolution. We witness something new every day and believe that this is the most that we can be surprised, but by the next day there is another remarkable discovery waiting for us.

From a massive supercomputer to a pocket size gadget, from letters that took days to reach their destination to delivering email in a few seconds, that era is not too far in which Howard Stark (of the Marvel Cinematic Universe) said that we would have “flying cars.”

Does the idea of creating ‘designer babies’, hybrids, glowing puppies that resemble jellyfish, flying elephants, or a completely new species seem attainable in coming years? Only time will tell…

For now, let us revisit the history of synthetic biology, for the story of synthetic biology has not only started with these ideas but has proved that it can be possible to redefine a lot of things that were previously considered unattainable- designing vaccines, drugs, and probiotics, creating milestones like the green revolution, the white revolution, and the list goes on. A decade ago, when biologists, bioengineers, computer scientists, and hardware developers came together, it was proposed that synthetic biology engineers should work with the same rhythm as computer scientists and should take inspiration from the earlier innovation in the microchip industry.

Synthetic biology is the branch of science that deals with modifying an existing organism to enable it to acquire new abilities for beneficial purposes. It does not completely restructure an organism, but rather harnesses the essential properties more effectively, while introducing some special elements. It’s like going to a hypermarket and buying all the requirements to make a dish and at last adding secret ingredients for the special taste. The secret ingredient here refers to the whole concept of synthetic biology.

In this area, everything starts from scratch, whether it’s DNA, RNA, or protein. Thus, the very first synthetic biology experiments were conducted to develop the recombinant DNA technology in bacteria, which led towards solving important problems in agriculture and healthcare. The approach for the design of models varies with different kinds of projects. One of them is natural selection which Darwin mentioned in his theory and is widely accepted till now by our scientific community. With the help of transduction and conjugation (a relationship between bacteria-virus and bacteria-bacteria to gain the benefit), ‘the magical gene’ gets transferred, and if it favors the bacteria, it becomes naturally selected. Later on, bacteria diversify to create a new army that has abilities that were not seen before.

RNA is considered as the main hero of central dogma because the process of transcription (DNA to mRNA) cannot be complete without it and the process of translation (mRNA to protein) cannot start without it. Engineering RNA with the aid of sensors and improving its efficiency is another approach to redefine biology

However, as Spiderman rightly said, ‘With great power comes great responsibilities.’ The same applies to this field as well. Along with the power, there are also several challenges that need to be tackled effectively.

One of the major challenges is to design specific models as they should mimic the biological problem for which they are designed. The problem increases especially with cell-based disease treatment.

Secondly, any project revolving around synthetic biology includes a hefty amount of investment of money, time, and brain, most of the time it’s not necessary that it gives satisfactory results. The constant war of product efficiency versus product cost is also another parameter to be considered.

Thirdly, designing immune cells that destroy cancerous cells, engineering microbes that create biofuels that can be put directly into a gas tank, and engineering food crops with higher yields per acre while using less fertilizer and water consumption are the ultimate goals of synthetic biology. But the question is, how easy or complex is it?

This talk by World Science Festival explains quite a lot about the past, present and future of synthetic biology.

But if we are to believe this will become a reality in a few years, then it also gives rise to a bigger question: what would be its consequences? Will it result in a similar situation like in The planet of Apes or the Netflix series Sweet tooth or the documentary Unnatural selection? If you haven’t watched them I would strongly recommend you to watch and make your brain a bit curious before diving into the synthetic biology field.
Nashrah Mubeen Writer

Disclaimer: The content of this article is meant for educational and creative purposes only, and will not be directly used for generation of profits. All rights and responsibilities, including the authenticity of the information presented in this article belong to the original authors and their publications (listed below in the Bibliography section), and there is no copyright infringement intended.

Bibliography

Science In Context

Biosensors: The Whats, Whys & Hows

Academia Plus

A biosensor is a shortened term for ‘biological sensor’, a combination of biological components (an enzyme, an antibody or nucleic acid) and a detector element. The use of biosensors has become popular in recent years and the widely accepted definition of a biosensor is “a self-contained analytical device that incorporates a biologically active material in contact with an appropriate transducer for the purpose of detecting the concentration of activity of chemical species in any type of sample”.

A molecular biosensor is a specialised and compact device that measures specific components in relation to our health and disease. These measurable components are called biomarkers. A biosensor is operated through a biological sample taken from our body, for example, a drop of blood.

How do Biosensors work?

A biosensor has two main functional parts- 

  • A detection system called bioreceptor – this can be an enzyme, an antibody or even living cells
  • A physico-chemical transducer – which helps to transform the signal captured by the bioreceptor into a readable measurement 

Biosensors are mainly categorized on the basis of the type of signal that is generated. For example-

Electrochemical biosensors – which measure changes in electric current or ion concentration

Optical biosensors – which measure optical changes such as absorbance, fluorescence, etc.)

Piezoelectric biosensors –  which measure changes in sound vibrations.

The above types can be used to detect a wide variety of biological components such as enzymes (electrochemical detection), antibodies (optical detection), and so on. 

So how and why are biosensors relevant? Let us find out.

Lately, in cancer research, biomarkers and electrochemical biosensors are used for more accurate diagnosis and preventive treatment. Biosensors hold great potential in cancer detection and monitoring the progression of tumour growth. Biomarkers i.e., the biological components detected by the biosensors are significant indicators in monitoring and providing better a better treatment approach. 

Biosensing is also applied in understanding the development of cardiovascular diseases. For instance, identifying and measuring biomolecules in bloodstream at low levels helps in evaluating diseased conditions.

Apart from this, we use biosensors quite frequently in our daily routine. For example-

  • Glucometer is the most well-known and popular biosensor. It is a glucose monitoring device which measures the glucose concentration in the blood. 
  • Pregnancy strip is commonly used to detect the presence of a specific antibody in the blood or urine to confirm pregnancy.
  • Wearable biosensors such as smart watches, blood pressure monitoring devices, etc. have proven to be a boon to today’s lifestyle and allow us to track fitness on daily basis.
  • COVID-19 antigen test – the newest invention that almost all of us are aware of because of the pandemic is also based on the principle of biosensing. This test is designed to detect the presence of Covid19 viral components antigens in our body.

The use of such biosensors and their extensive medical applications makes it very helpful for patients and doctors to get immediate results and optimize the treatment plan on time, while enabling self-management of the disease. It also allows for an early diagnosis and provides successful treatment plans as the disease progresses.

With the many beneficial applications of biosensors, nowadays a number of disorders like diabetes can be effectively monitored at home. It provides a better interface between physicians and patients and also helps in better management, while promoting the approach of personalised healthcare. 

Their enormous applications in the field of pharmacy, biomedical and healthcare sectors further put them as one of the major focus areas for future innovations. We are only getting started!
Guneet Kaur Writer

Disclaimer: The content of this article is meant for educational and creative purposes only, and will not be directly used for generation of profits. All rights and responsibilities, including the authenticity of the information presented in this article belong to the original authors and their publications (listed below in the Bibliography section), and there is no copyright infringement intended.

Bibliography

Science In Context

The use of CRISPR in Neuroscience

Academia Plus

“The brain is the organ of destiny. It holds within its humming mechanism, secrets that will determine the future of the human race”

The above words by Wilder Penfield rightfully describe what a magical organ the brain is, and how important the field of neuroscience is to the advancement of the human race.

‘Neuroscience’ as a subject is quite vast, integrating principles from anatomy, molecular biology, developmental biology, chemistry, computer science, philosophy, mathematics, linguistics, and medicine, to study the functioning of our brain and to answer relevant questions in the field. Neuroscientists do not just study behaviour and emotions, but also understand the importance and relevance of essential body functions such as sleeping and breathing. Apart from this, the study of neurodegenerative disorders is a major part of this field. Several technological advancements have paved the way for a better understanding of this field, some of the latest being the CRISPR-Cas9 technology.

CRISPR-cas9 is a precise gene-editing technology that was discovered by Dr. Jennifer Doudna and Dr. Emmanuel Carpentier who won a Nobel prize in chemistry for the same, in the year 2020. CRISPR is the simplest, and the most versatile method of gene editing which has created a buzz in the world of science geeks by promising a wide range of future applications and solutions that did not exist before. Using CRISPR, scientists and researchers can remove, add or alter sections of DNA sequences which can change the overall functions of the entire genome (and therefore, human physiology and metabolism itself!). Due to its cost-effectiveness and an ability to edit DNA sequences in a relatively short amount of time, the CRISPR technology has totally revolutionised the field of biology.

Before we understand its specific use in the field of neuroscience, let us have a quick recap of how the technology functions. CRISPR-cas9 system is essentially made up of two key components:

  • Cas9 enzyme: This component is responsible for making ‘cuts’ at specific locations of the DNA, in a way that fragments or genes can be either added or removed at these particular locations. This component is therefore also referred to as a ‘molecular scissor’.
  • Guide RNA (gRNA): This component is a small fragment of a pre-designed RNA sequence that is complementary to the ‘target’ DNA sequence, and ‘guides’ the Cas9 to the appropriate location on the DNA, to introduce the ‘cut’.

After the cut is made, the cell recognizes this as damage that needs to be repaired and through this newly repaired molecule, permanent changes are introduced in the DNA sequence.

CRISPR-Cas9 has potential applications in different fields, especially in treating conditions that have a genetic origin, as well as gene therapy- in which a defective gene can be replaced with a ‘better’ gene.

Although the use of CRISPR in the field of neuroscience still sounds a lot like science fiction, it is slowly becoming a reality. CRISPR technology can not only be used for research but also as a potential tool for treating neurological disorders-

  • Identification of neural networks: CRISPR was used for the first time in 2020 to alter the transmission rate in neurons, which revealed important aspects of neural network behaviour that is seen in seizures and epilepsy. This gave hope that CRISPR could also be used as a potential treatment for epilepsy by altering neuron activity.
  • Identification of important genes: Some brain disorders such as schizophrenia and autism are suspected to have a genetic basis. Identification of the genes, possible mutations in them as well as the neural circuits that may be affected by the mutations leading to the development of these diseases, can be easily undertaken by the CRISPR technology. 
  • Potential treatment of hereditary disorders: Huntington’s disease (HD) is a hereditary disorder which leads to progressive degeneration of nerve cells. Combination of CRISPR technology with gene therapy is a promising approach towards treatment of such diseases.
  • Generation of model organisms: CRISPR has been successfully used in the rapid generation of model organisms, which can further lead to the identification of uncharacterized genes, as well as the study of specific proteins and their functions in neurological disorders. These model organisms can range from rats and mice to more complex primate models. This technology has been successfully used in the alteration of genes of species such as killifish and salamanders, which are popularly used to understand and examine ageing as well as tissue regeneration.

While all this sounds fancy and exciting, there are also limitations to the use of CRISPR in neuroscience, due to the following reasons:

  1. Stem cells or neurons have a very active response system to DNA damage which means that even when there is only a single cut from the Cas9 enzyme, there is a high probability that the cell will die as a result of toxicity.
  2. The blood-brain barrier (BBB) poses a major problem to CRISPR as the required reagents cannot enter the BBB and make changes at the genetic level.

As is the case with all technological advances, this one too comes with its own set of strengths and weaknesses, and moreover, considering the degree of genetic manipulation introduced by this technology, it is necessary to ensure absolute specificity and precision.

However, it cannot be denied that CRISPR/Cas9 is a wonderful tool for neuroscientists all around the world, to unravel the working of the brain and to understand the magic that takes place within!
Sanjhi Sardana Writer

Disclaimer: The content of this article is meant for educational and creative purposes only, and will not be directly used for generation of profits. All rights and responsibilities, including the authenticity of the information presented in this article belong to the original authors and their publications (listed below in the Bibliography section), and there is no copyright infringement intended.

Bibliography