What is the Difference Between Cloning and Subcloning

The main difference between cloning and subcloning is that cloning is the production of clones of organisms or copies of cells or DNA fragments whereas subcloning is a technique used to move a particular DNA sequence from a parent vector to a destination vector. Furthermore, cloning uses primary cDNA or gene while subcloning involves the subsequent manipulation of the clone by changing the vector or primary insert.

Cloning and subcloning are two techniques in molecular biology to manipulate the genomes of organisms by introducing DNA fragments of interest.

Key Areas Covered

1. What is Cloning
     – Definition, Method, Importance
2. What is Subcloning
     – Definition, Method, Importance
3. What are the Similarities Between Cloning and Subcloning
     – Outline of Common features
4. What is the Difference Between Cloning and Subcloning
     – Comparison of Key Differences

Key Terms

Cloning, Expression Vector, Insert, Parent Vector, Subcloning

What is Cloning

Cloning is a technique in molecular biology that helps to make multiple molecules of a DNA fragment of interest. Therefore, it is also known as molecular cloning. It can be used to amplify both coding and non-coding DNA such as genes and regulatory DNA sequences including promoters, respectively. Moreover, it has a wide variety of applications from genetic fingerprinting to protein production in large scale.

Figure 1: Molecular Cloning

Furthermore, the steps in cloning are as follows:

1. Fragmentation – breaking apart a strand of DNA by restriction digestion
2. Ligation – gluing together pieces of DNA in the desired sequence
3. Transfection – inserting the newly formed pieces of DNA into cells
4. Screening/selection – selecting out the cells that were successfully transfected with the new DNA

However, cloning also refers to the production of a large number of genetically-identical individuals from a parent organism. It can occur naturally in the environment in the form of reproduction. On the other hand, it can be performed inside the laboratory as done in tissue culture techniques. 

What is Subcloning

Subcloning is a technique in molecular biology that helps to move the insert DNA from the parent plasmid to a second vector. Here, the second vector can be an expression vector, which allows the expression of the DNA fragment. Moreover, it can be used to change the expression under a different promoter. Or else, the second vector may contain special characteristics such as specific marker for antibiotic selection or fluorescent expression.

Figure 2: Subcloning

Moreover, the steps in subcloning are as follows;

1. First, release and purify the insert from the parent vector by restriction digestion
2. Ligate the insert into a prepared destination vector
3. Then, transform the ligation reaction into competent bacterial cells
4. Screen the transformed cells for the insert

Similarities Between Cloning and Subcloning

• Cloning and subcloning are two techniques of molecular biology to manipulate genomes.
• Both of these are important to introduce a DNA fragment of interest into the genome of an organism.
• Moreover, they are important in the construction of genome libraries as well.
• Also, both methods rely on restriction digestion and PCR.

Difference Between Cloning and Subcloning

Definition

Cloning refers to the process of creating clones of organisms or copies of cells or DNA fragments while subcloning refers to a technique used to move a particular DNA sequence from a parent vector to a destination vector. Thus, this is the main difference between cloning and subcloning.

Importance

Moreover, cloning can introduce a DNA of interest to the genome of a particular organism while subcloning can introduce the DNA fragment of interest into a second vector.  

Type of Vectors

Type of vectors is another difference between cloning and subcloning. Cloning often uses cloning vectors while subcloning may use expression vectors. 

Conclusion

Cloning is a technique in molecular biology that helps to introduce a DNA fragment of interest into a host organism or to construct DNA libraries while subcloning is another technique in molecular biology that helps to introduce a DNA fragment from a parent vector into another vector as well. Therefore, this is the main difference between cloning and subcloning.

References:

1. “Common Cloning Applications and Strategies.” Thermo Fisher Scientific – US, Available Here. 

Image Courtesy:

1. “Figure 17 01 06” By CNX OpenStax (CC BY 4.0) via Commons Wikimedia   
2. “Steps of Molecular Cloning” By Alexpicardal97 – Own work (CC BY-SA 4.0) via Commons Wikimedia