Gene synthesis has revolutionized genetic research over the past twenty years by allowing the convenience of DNA storage for a wide range of genome sizes. These libraries have allowed researchers to archive the genes of interested and be able to obtain each gene with relative ease at his or her leisure. Another great advantage ofgene synthetic libraries is the convenient location of the genetic foundation of the organism at your disposal. The genetic foundation can either be stored as the entire genome or more specifically the coding regions of the genome. Gene libraries are mainly broken down into two distinct categories: genomic libraries and cDNA libraries. The two have the same principles and similar output, but are created in different ways and have many different aspects.

How are genomic libraries constructed?

The genomic libraries is representative of the organism’s entire genome, making the library quite large. 

The process of creating a genomic library is as follows: first the selected DNA is isolated from the cells by a specific restriction endonuclease. The resulting DNA fragments are then inserted into a selected vector using DNA ligase. Once the DNA is located within the vector, the vector is inserted into a bacteriophage to be amplified. After amplification, the cloned DNA is then isolated again and inserted into a genomic library. This process is then repeated until the entirety of the organism’s genome is isolated, amplified, isolated again, and inserted into the genomic library. Since it is the entire organism’s genome is located in these libraries, including both coding and noncoding regions, these libraries can become quite large. Genomic libraries offer many advantages, such as being able to study gene regulation, or off target effects of a particular mutation. The large amounts of data allow researchers to better understand how mutations, located outside of the coding region of a gene, affect the organism. This extra information is essential to better understand certain mutations, but the large amounts of data can sometimes be problematic. In conclusion, genomic libraries offer more information about the organism, but in turn are more laborious to create and are much larger in size when compared to cDNA libaries.

How are cDNA Library Constructed?

cDNA library is representative of the organism’s exonic regions, meaning that only the coding regions of the genome are recorded and stored in the library. 

The process of creating a cDNA library is as follows: mRNA is isolated from a cell of interest and collected. Reverse transcriptase is then used to generate the double stranded cDNA corresponding to the mRNA sequence. Once this is complete, the DNA ends are cleaved to become single stranded and is inserted into a selected vector using DNA ligase. The vector is then inserted into a bacteriophage and amplified. After amplification, the cDNA is isolated and collected in the cDNA library. The cDNA library is much smaller than that of genomic libraries as it only represents the exonic portion of the organism’s genome. This small size is not always problematic, cDNA libraries offer a unique approach to study variant mutations present within coding regions of a gene. In addition to studying variant mutations located within a gene, cDNA libraries also offer a more convenient approach to study protein function, interaction and expression.

What Are the Limitations of cDNA Libraries?

Lack of Regulatory Elements: One major limitation of cDNA libraries is their lack of regulatory elements, meaning that they do not provide insights into gene regulation processes since these libraries only include expressed genes' coding regions.

Reduced Gene Diversity: Due to being assembled from mRNA transcripts, cDNA libraries often only represent actively being transcribed genes, with lower expression or tissue-specific genes not being adequately represented.

Bias towards Highly Expressed Genes: CDNA libraries tend to favor highly expressed genes; high expression levels lead to more abundant mRNA production and thus overrepresentation in the library, making it hard to study genes expressed at lower levels.

Why Are DNA Library Prep Steps Critical in Understanding the Genome?

DNA libraries enable targeted research, helping scientists to discover genetic mutations, understand diseases and develop innovative treatments. By knowing which genes to investigate first, researchers can expedite their findings and apply them immediately in real-world settings. DNA library preparation is therefore an integral step that makes genetic research much more accessible and actionable.

At Synbio Technologies we offer gene synthesis service verify the genes you are interested.A DNA library, either constructed by you or our team of experts, will be generated for a competitive price and in an efficient timeframe. We offer virtually any library type to fit your need, ranging from scanning, to triplet codon, to modular. 

In addition to this Synbio Technologies also offers error-free gene sequence with a 100 percent guarantee of the generated sequence quality. This also allows us to create a synthetic gene library, generated by genes of interest without the physical copy of the gene being needed. Synbio Technologies offers many quality assessments to make sure that your gene library is exactly how you designed it to be and is as effective as possible. With the high quality library Synbio Technologies offers, and at a competitive price, your library will be synthesized and be ready to analyze with ease and convenience.