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rDNA and cDNA

rDNA and cDNA: A Brief Overview

Last updated date: 29th Mar 2023
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Modern science has already been transformed by DNA technology. Numerous hints about the secrets of human behaviour, illness, evolution, and ageing can be found in DNA. Cloning, PCR, recombinant DNA technology, DNA fingerprinting, gene therapy, DNA microarray technology, and DNA profiling are a few examples of contemporary developments in DNA technology. The fields of health, forensic science, environmental research, and national security have already started to be influenced by these technologies. Two types of DNA that can be created using modern DNA technologies are rDNA and cDNA.

What is rDNA?

Recombinant DNA technology is the name given to the process of creating artificial DNA by fusing DNA from various sources with various genetic components. Genetic engineering is the term used to refer to recombinant DNA technologies.

In 1968, Swiss microbiologist Werner Arber made the discovery of restriction enzymes, which led to the development of recombinant DNA technology. It's harder than it sounds to splice the desired gene into the host's genome. It entails choosing the ideal vector with which to integrate the intended gene and create recombinant DNA after choosing the appropriate gene to be administered to the host.

What is rDNA?

Reverse transcription, the process of creating DNA from an RNA template, results in complementary DNA (cDNA). Reverse transcriptases (RTs) direct the synthesis of the first strand of cDNA, which can be used directly as a template for the Polymerase Chain Reaction, using an RNA template and a short primer complementary to the 3' end of the RNA (PCR). Reverse transcription and polymerase chain reaction (RT-PCR) allows for the detection of low-abundance RNAs in a sample and the creation of the corresponding cDNA, making it easier to clone low-copy genes. As an alternative, DNA Polymerase I and DNA Ligase can be used to double-strand the first-strand cDNA.

What Similarities Do rDNA and cDNA Share?

  • These kinds of DNA can be created using current DNA technology.

  • Both DNA types are created by unique enzymes.

  • They are created in particular labs.

  • There are several uses for both forms of DNA in biotechnology, medicine, and agriculture.

Differences Between rDNA and cDNA



The DNA is recombinant.

It is mRNA's complementary DNA or complementary DNA.

Formed through the fusion of DNA from two distinct species.

Reverse transcription, which is performed by the enzyme reverse transcriptase, is used to create it from the mRNA.

Recombinant DNA refers to the process of introducing a particular variant of the desired gene into a targeted gene.

At the 5' end of cDNA are polyadenylated sequences.

For transformation, gene therapy, etc., rDNA is utilised.

cDNA is used as a tool in gene cloning and other scientific experiments.

rDNA is present in the gene library.

There are cDNAs in the library.

Interesting Facts

  • Human dna is 99.9% similar

  • The size of DNA in humans is 2.2 metres larger than the cell size.

  • DNA fingerprinting is the technique used to identify criminals, and also used for paternity testing

  • Viruses are not living, they do not get any place in whittaker's classification

Important Questions

1. What is cDNA technology?

Ans: cDNA microarray is one of the important methods for studying gene expression in many organisms. It is also used for mapping of genomic DNA and polymorphism.

2. What is rDNA used for?

Ans: rDNA is used to manipulate DNA fragments to study them in the lab. It uses many laboratory methods to put a piece of DNA or gene of interest in a vector cell.

3. What is the process of making cDNA?

Ans: The process of formation of DNA from RNA through the reverse transcription leads to formation of cDNA. cDNA is used as a template in many downstream applications.

Practice Questions

  1. What does cDNA mean?

  2. Why is cDNA used in recombinant technology?

  3. How is mRNA converted to cDNA?

  4. What is the difference between cDNA and DNA?

Key Features

  • In this article, we have studied about cDNA and rDNA, differences and similarities between cDNA and rDNA.

  • Modern DNA technologies have been discovered to be helpful in genetic engineering, illness prevention, boosting agricultural productivity, diagnosing ailments, and catching criminals.

  • Two forms of DNA that can be created using current DNA technologies are rDNA and cDNA. By combining the DNA of two various creatures, rDNA is created. On the other side, reverse transcription is used to create cDNA from mRNA. So, this sums up how rDNA and cDNA vary from one another.

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FAQs on rDNA and cDNA

1. What is rDNA? Write its applications.

The universal code for inheritance in all living things is deoxyribonucleic acid (DNA). Recombinant DNA (rDNA) is made up of two separate bits of DNA from other organisms that have been fused. Recombination DNA from the two parent organisms during sexual reproduction is also referred to as recombinant. Recombinant DNA is most frequently used in fundamental research, where it is crucial to the majority of ongoing projects in the biological and biomedical sciences. Genes' locations, functions, and sequences are all discovered via recombinant DNA.

2. What do genes do?

Genes are little DNA segments that contain protein-coding information. In essence, the so-called gene products are the instructions for creating a certain protein. The majority of genes lack traits unique to the creature in which they are present. It is impossible to identify "fish genes" or "tomato genes" by looking at the gene sequence alone; it is also difficult to establish the creature from which a gene originates.

3. How long does cDNA remain stable?

Reverse transcription, the process of creating DNA from an RNA template, results in complementary DNA (cDNA). The stability testing is now being conducted by ECACC, and as soon as the results are ready, they will be shared on the Culture Collections website. At this time, we advise using the cDNA within six months of production. The lot number can be used to establish the date of manufacture.

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