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What is RT PCR? |Reverse Transcriptase PCR

What is RT PCR? |Reverse Transcriptase PCR
What is RT PCR

RT PCR or Reverse Transcriptase PCR is a test used to detect retroviral diseases like AIDS. It gained popularity during coronavirus outbreak.

Before knowing about RT PCR, please refer PCR or Polymerase chain reaction first here – https://sciencebirdie.com/2020/06/17/what-is-pcr-polymerase-chain-reaction-explained/

PCR or polymerase chain reaction is the technique in which the DNA is amplified and the billion DNA copies are made. But, it has exceptions like it can only detect only DNA viruses. Therefore, detection of RNA viruses like retroviruses cannot be possible.

What is RT PCR

This is where the RT PCR has the significance.

Working mechanism

Viruses like Coronavirus have RNA as the genetic material, therefore, the detection using the traditional PCR becomes impossible.

So, scientists convert RNA to DNA using an enzyme called Reverse transcriptase, the process known as Reverse Transcription. On the other hand, the conversion of DNA to RNA is called Transcription.

What is RT PCR
Thermocycler or PCR machine used in PCR technique

Steps in RT PCR

Firstly, the RNA converted to DNA using reverse transcription.

The DNA then transferred to the thermocycler machine or the PCR machine.

Afterwards, the steps denaturation, annealing and extension followed and the billion DNA copies extracted.

Please refer the PCR steps here – https://sciencebirdie.com/2020/06/17/what-is-pcr-polymerase-chain-reaction-explained/

Advantages

Coming to advantages, it had got more in addition than the traditional PCR.

Highly sensitive as the RNA involvement in it.

Highly specific, with more accuracy than PCR.

Requires less than 4 hours in diagnosis, moreover, the laboratories take up to 6-8 hours.

As the genetic material placed in a closed tube with enzymes, it has low potential contamination.

RT PCR in Corona test

Nowadays, with Coronavirus being prevalent, the RT PCR use got very much boosted up.

What is RT PCR

Firstly, the victim’s blood sample is taken then using several enzymes the RNA is extracted and converted to DNA and with PCR many copies are made.

Now, the DNA bases are made to pair with another bases tagged with markers. Further, the pairs are examined through fluorescence technique. If there are abnormalities, in the pairs the pairing does not occur. In other words, the person stated positive in the test.

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What is PCR? | Polymerase Chain Reaction Explained

What is PCR? | Polymerase Chain Reaction Explained

What is PCR?

Polymerase chain reaction is a technique through which the DNA is ampified and desired copies of the DNA is extracted.

What’s with the name?

Polymerase stands for enzyme, chain means the type of reaction. PCR is a chain reaction. Therefore, it is an Enzyme linked chain reaction, which makes copies of the DNA.

PCR – Uses

This technique is used to diagnose infections, above all to detect viral infections.

For instance, The blood sample of the patient is taken and the viral DNA is extracted and amplified.

Used in crime investigation, as it involves DNA. Also, in branches of Biotechnology, Forensic and molecular biology.

Used in Genetic research

Materials required in PCR

Now, you have understood what is pcr and it’s uses. To run a reaction ingredients are required, so here are the ingredients or materials required for the PCR:

1) Thermal cycler or PCR machine

To understand the PCR, first of all it is necessary to understand what is PCR machine. PCR machine or thermal cycler machine is where the reaction takes place. Above all, it is the main machinery in which the DNA copies are made.

what is pcr

Contains small tubes to which the ingredients mentioned below are added.

2) Taq polymerase

The DNA polymerase used here in PCR, it is extracted from a bacteria called Thermus aquaticus which can withstand high temperature. Similarly, this enzyme too can withstand high temperatures.

It is ideal for PCR, because Taq polymerase is active around 70 degree celsius. Also, it is very heat stable.

what is pcr

3) Primers

Primers are short sequence nucleotides. It provides a starting point to initiate the reactions. Moreover, it helps to choose an exact well defined portion to amplify.

3) Nucleotides

These are the basic units of DNA. Required here to make copies with the denatured parts of the DNA.

4) DNA template

This is the original segment of DNA we want to amplify, the target DNA. To clarify, the amplification starts in this template.

Now, we are set with the ingredients. In addition, we are left to initiate the reaction.

what is pcr

The process of PCR is split into three parts:

Denaturation, Annealing and Extension

Here, is the explanation step by step:

Denaturation

The first step in PCR in which the temperature raised to 96 degree celsius. In other words, done to seperate the strands of the original DNA template. That is, one DNA template into two. Here, we will get two separate strands of the DNA.

Annealing

In this second step, the machine temperature is reduced to 55 degree celsius.

After that, it results in the primer attachment to the target sequence of the stranded DNA or denatured DNA,

Extension

The last step in which the free nucleotides are required.

The temperature is increased to 72 degree celsius, meanwhile , it results in the activation of Taq polymerase. It will extend the primers to make new DNA strands.

These are the steps and the reaction occurs like a chain in which from one DNA we get two copies, further from two we get Four copies and so on, so for 100 reactions it can produce billions of copies.

Nanotechnology used in medicine


By Ankita Chouhan Bsc (GEN)

Nanotechnology is a revolutionary technology to treat various medical diseases. Father of nanotechnology is Richard Feynman. It acts like a miracle for treating chronic diseases such as cancer and AIDS. It focuses on production of cheap medicines, reduce side effects of medicines, treat chronic diseases and manufacture to reduce pain and bleeding during surgery. It works on the principle of targeted drug delivery as a drug that directly injected into the effective cells as large amount of drugs affects the healthy cells.

Carbon nanotubes (CNTs)are very thin cylindrical tubes which can penetrate through the cell membrane and provide drugs to the affected cell. Nano sensor chips are also used to detect early stage of Cancer as it possess thousands of CNTs in it. Other than chips, gold nanoparticles are also used to detect cancerous cells. Doxil, cornel dots (C-dots), abraxane etc are some examples of commercially used drugs containing nanoparticles.

In case to treat AIDS we use HAART (High activity antiviral therapy). As we are aware HIV is not curable but through HAART therapy replication of HIV can be inhibited which in turn leads to a life long treatment. HAART therapy was founded in 1996 which involves a combination of three antiretroviral (ARV) which includes integration inhibitors which prevents the HIV inserting is genetic code into the DNA of the infected cell.

Nanotechnology also plays an important role in bone implantation or replacement surgery. Artificial bones made up nanoparticles are much lighter and stronger than standard artificial bones used in the surgery. With the help of nanotech tools such as Arthroscope are also developed which consists of numerous Nano cameras and Nano lights which help in less time consuming and incision free surgery.