Extraction Of DNA By Using Magnetic Deep-Eutectic Solvent: Literature Review
DNA has been discovered over half century ago. Since then, a research on DNA has become a subject of intense interest. DNA is a biomacromolecule that plays important role in the living organism. This is due to the fact that it stores the genetic information for cell replication and transcription. The potentials of DNA were increasingly recognized especially in the applications of biosensors, catalytic membranes, absorbing membranes and support for catalysts.
Tan S. C. and Yiap B. C. (2009) says extraction of DNA, RNA, and protein is the basic method used in molecular biology. These biomolecules can be isolated from any biological material for subsequent downstream process, analytical, or preparative purposes. However, the conformation of DNA is not able to be maintained. This is because the structure of DNA is highly influenced by the solvent. Both aqueous and organic solvents are widely used as an extraction media or molecular solvent for DNA solvation. The stability of biological structure of DNA is mainly depends on the water molecules. Particularly, the conformational and stability of DNA are controlled by the interactions between DNA and nearby water molecules. DNA is considered as stable in aqueous media, however, due to the slow hydrolytic reactions such as deamination and depurination, it may cause denature to the conformation of double helical DNA.
Futhermore, Yusof R. et al. (2016) says DNA is unstable in aqueous solution causing denaturation of the nucleic acid structure after one month of storage at ambient temperature. Moreover, other than water and temperature, the ambient environment also plays a big role in stability of DNA conformation. Examples for ambient environment are different buffer conditions, such as pH and types of buffer solutions, concentrations of molecules, salt concentrations and different type of non-aqueous solvents.
Based on previous studies on DNA in non-aqueous solutions, it revealed that most organic solvents such as methanol, phenols, chloroform and DMSO, whether neat or in a mixture with water, all spontaneously denature the conformation of double helical DNA. Ionic liquid (ILs) which are one of the non-aqueous solvent have attracted many attentions due to its interesting properties such as mom-toxic, good solubility and high conductivity. They offer unique opportunities as alternatives to aqueous and non-aqueous solvents in DNA biotechnology. Nevertheless, Yusof et al. (2014) says due to the problems with high cost, purification and toxicity, deep eutectic solvents (DES) has been discovered. It is an alternative for ILs which are biodegradable, cheap and easy to prepare. DES share the same properties with ILs. Hence, DES can replace ILs in many applications due to its shared properties. Moreover, DES have both ionic and non ionic species and are connected by a hydrogen bonding network.
According to Tavakol H. and Keshavarzipour F. (2017), magnetic nanoparticles have been employed as an important as an important type of support for various catalysts. This is due to their properties, which are high surface area, superparamagnetic properties, low toxicity, ease of preparation, high potency for surface functionalization and facile recovery using external magnetic field. However, coating them with DES for the extraction of DNA has not been reported, which seems a useful way to create a new way to extract DNA.
The process of extraction and purification of nucleic acids used to be complicated, time-consuming, labour-extensive, and limited in terms of overall throughput. Nowadays, they are many specialized methods that can be used to extract pure biomolecules, such as solution-based and column-based protocols. Manual method has certainly come a long way over time with various commercial offerings which included complete kits containing most of the components needed to isolate nucleic acid. However, most of them require repeated centrifugation steps, followed by removal of supernatants depending on the type of specimen and additional mechanical treatment.
According to Saiyed Z. M. and Ramchand C. N. (2007), in recent studies, magnetic separation technology by using magnetic particles is a quick and easy method for sensitive and reliable captures of specific proteins, genetic material and other biomolecules. The yields of the isolated DNA with magnetic method were higher and or equivalent to the conventional procedures in all the samples tested. Additionally, the magnetic method takes less than 15 minutes to extract DNA as against several hours taken by conventional protocols. Therefore, it is an advantage to study the extraction of DNA by using magnetic deep eutectic solvents.
