Magnetic beads are the main tool of new nucleic acid extraction technology. Magnetic beads have the characteristics of monodispersity, high specific surface area, good dispersibility and resuspension, faster magnetic response, better water solubility, and more active functional groups. They can form a “quasi-homogeneous” reaction system. It can combine, react and separate with the target fragment with great efficiency and specificity. Under the directional control (automation) of the external magnetism, the target molecule can be separated from the complex biological system, soil, water and other samples through adsorption, cleaning, elution and other operations. Next, I will share with you the common types of magnetic beads and their development prospects.

Common types of magnetic beads

1. Unmodified magnetic beads

The magnetic core is Fe3O4 magnetic group, which is first coated with derivatized silane, and then coated with polymer. In the early days, some manufacturers would directly mix Fe3O4 and polymer, grind and sieve them out, and even mix Fe3O4 powder into the beads during the emulsion polymerization process. However, the magnetic beads obtained by these methods have some problems. For example, the exposure of iron (magnetic leakage) will affect the experimental results of DNA polymerase users. Iron can reduce the activity of the polymerase and adversely affect many cells. In order to improve the stability of magnetic beads and expand their application fields, scientists add different materials to the magnetic beads in different proportions, such as polystyrene, cobalt dioxide (non-paramagnetic), agarose and so on. Generally speaking, a polymer outer layer is added to the surface of the magnetic bead, or a relatively stable outer shell such as silica is added. The purpose of coating is to protect the inner core of the paramagnetic bead and prevent it from being oxidized; in addition, this These coating materials have good biocompatibility and are easy to couple with various functional groups.

2. Magnetic beads with universal specific ligands

This type of magnetic beads captures a group of target molecules and is versatile. It is often used for nucleic acid extraction and purification in scientific research and molecular diagnostics, and purification of PCR amplified products; it can also be used in high-throughput second-generation sequencing platforms, such as Illumina Sequencer blunt-ended fragment DNA screening, etc. In short, through various chemical modifications and chemical reactions, hundreds of general-purpose specific ligand magnetic beads with different functions can be obtained, and the application fields are very wide. It can be used not only for nucleic acid purification, but also for protein and polysaccharide purification and immunoassay detection. In addition, this type of magnetic beads is also widely used in modern biomedical chemical technology and research for the screening and delivery of biochemical macromolecules and small molecule drugs.

3. Magnetic beads with specific recognition groups

This kind of magnetic beads can enrich and separate target cells, and can also separate out hybrid cells by specific adsorption (using magnetic beads with specific antibodies to non-target cells); in some specific experiments, such as positive in molecular cloning systems For cell separation, the vector encodes the cell surface marker protein, and the successfully transfected cells can be separated by using magnetic beads coupled with specific antibodies (for the cell surface marker protein expressed by the vector).

The development prospects of magnetic beads

In recent years, magnetic beads have been gradually applied in fields such as biomedicine, cytology, and bioengineering. However, the magnetic beads and magnetic bead series produced by foreign companies still have a great advantage in the application market. It started late in China, but in recent years, a number of high-quality companies have also emerged to produce magnetic bead products, such as Aisen Biotech. High-sensitivity, high-throughput, and high-efficiency magnetic separation and purification technology has shown broad application prospects in the biomedicine and clinical diagnostic markets. The huge market demand will inevitably drive domestic companies to develop and produce world-class magnetic bead products. Let us wait and see!

The common types and development prospects of magnetic beads are generally introduced as described above. Aisen Biotechnology produces nucleic acid extraction products with nano-biomagnetic beads as the core. If you have related requirements for Nucleic Acid Extraction Kit, please call for consultation.

The nucleic acid extraction system is a biomedical system designed for automatic magnetic bead method nucleic acid extraction. You only need to add the sample to be extracted to the matching kit, put the kit into the extraction system, run the edited program that comes with the system, and complete a round of sample nucleic acid extraction in 15 to 30 minutes. The use of magnetic bead method nucleic acid extraction system is generally divided into two types: suction method and magnetic rod method.

ONE. The characteristics of the magnetic bead method of nucleic acid extraction system

1.Able to realize automation and high-throughput operation.
2. The operation is simple and fast.
3. Safety and environmental protection.
4. High purity and high yield.
5. No pollution and stable results.
6. Low cost, convenient for wide application.

TWO. Use method of magnetic bead method nucleic acid extraction system

1. Suction method

Also called pipetting method, nucleic acid extraction is achieved by immobilizing magnetic beads and transferring liquid. Generally, the transfer is achieved by controlling the mechanical arm through the operating system. The extraction process is as follows:

① Lysis: Add the lysis solution to the sample, realize the mixing and full reaction of the reaction solution through mechanical movement and heating, cell lysis, and release of nucleic acid.

②Adsorption: Add magnetic beads to the sample lysis solution and mix them thoroughly. The magnetic beads have a strong affinity for nucleic acids under high salt and low pH values ​​to adsorb nucleic acids. Under the action of an external magnetic field, the magnetic beads are separated from the solution. Use the tip to remove the liquid and discard it to the waste tank, and discard the tip.

③Washing: Remove the external magnetic field, replace with a new tip, add washing buffer solution, mix thoroughly to remove impurities, and remove the liquid under the action of the external magnetic field.

④Elution: Remove the external magnetic field, replace with a new tip, add elution buffer, mix thoroughly, and the bound nucleic acid is separated from the magnetic beads to obtain purified nucleic acid.

2. Magnetic rod method

The magnetic rod method realizes the separation of nucleic acids by fixing the liquid and transferring the magnetic beads. The principle and process are the same as the suction method, but the difference is the method of separating the magnetic beads and the liquid. The magnetic rod method is to separate the magnetic beads from the waste liquid through the adsorption of the magnetic beads on the magnetic rod, and put them into the next liquid to realize the extraction of nucleic acid.

THREE. Precautions for the use of magnetic bead method nucleic acid extraction system

1. The installation environment of the system: normal atmospheric pressure (altitude should be lower than 3000m), temperature 20-35℃, typical use temperature 25℃, relative humidity 10%-80%, unobstructed air flow is 35℃ or below.
2. Avoid placing the system close to a heat source, such as an electric heater; at the same time, to prevent short circuits of electronic components, avoid splashing water or other liquids into it.
3. The air inlet and exhaust vent are located on the back of the system, while avoiding dust or fibers from gathering at the air inlet and keeping the air duct unobstructed.
4. The nucleic acid extraction system is at least 10cm away from other vertical surfaces,
5. Grounding of the system device: In order to avoid electric shock accidents, the input power cord of the system device must be grounded.
6. Keep away from live circuits: Operators are not allowed to disassemble the system without authorization. Replacement of components or internal adjustments must be completed by qualified professional maintenance personnel. Do not replace components when the power is turned on.

At present, the magnetic bead method nucleic acid extraction system is widely used in various fields such as environmental microbial testing, food safety testing, blood transfusion safety, forensic medicine identification, disease control centers, clinical disease diagnosis, biological research, and animal husbandry.

Magnetic beads play an important role in nucleic acid extraction. The specific process is to first lyse the cells, then combine nucleic acids with magnetic beads through the binding solution, and use washing solution to wash away residual protein and salt ions, and then combine nucleic acids and magnetic beads. Separate. Seeing that the process is very simple, there are actually many factors that influence it. Next, I will tell you what are the factors that affect the extraction of magnetic beads.

1. The binding capacity of magnetic beads and nucleic acid

The top priority of the magnetic bead method for nucleic acid extraction is the adsorption capacity of the magnetic beads and nucleic acid, which directly affects the yield of nucleic acid extraction. In order to improve the performance of magnetic beads for binding nucleic acids, various magnetic bead manufacturers have tried various methods, but there are no more than two types of magnetic beads on the market: ionic bond magnetic beads and covalent bond magnetic beads. Ion-bonded magnetic beads are represented by silica gel-based magnetic beads. This type of magnetic beads is more and more due to their manufacturers, and there are endless kits on the market, but the principles are similar. The other type of covalently bonded magnetic beads is the cellulose membrane magnetic beads. Both types of magnetic beads cover most of the fields of nucleic acid extraction: medical, scientific research, blood station, disease control, forensic and other fields. The products also include whole blood DNA/RNA extraction, plants, animal tissues, saliva, cells, bacteria, viruses and other samples.

2. The magnetic force on the surface of the magnetic beads

The magnetic force on the surface of the magnetic beads is also one of the factors affecting nucleic acid extraction. No matter how strong the magnetic beads are for nucleic acid binding, if the magnet has a limited adsorption capacity, many magnetic beads will be lost during operation, and nucleic acid will be lost indirectly. Because of the special nature of the cellulose film, its ability to shield magnetic properties is poor, so the magnetic force on the surface of the cellulose film magnetic beads is stronger, and it is easier to adsorb tightly near the magnetic stand.

3. Equipment operation mode

At present, there are two main types of automation equipment: magnetic rod method and suction method. Suction method, also called pipetting method, is to achieve nucleic acid extraction by fixing magnetic beads and transferring liquid. Generally, the operating system controls the robotic arm to achieve the transfer, and the nucleic acid extraction is achieved through lysis-adsorption-washing-elution; magnetic rod The method is to realize the separation of nucleic acid by fixing the liquid and transferring the magnetic beads. The principle and process are the same as the suction method, but the difference is the method of separating the magnetic beads and the liquid. The magnetic rod method is to separate the magnetic beads from the waste liquid through the adsorption of the magnetic beads on the magnetic rod, and put them into the next liquid to realize the extraction of nucleic acid.

The main factors that affect the extraction of magnetic beads are the above three types. You can refer to them when choosing magnetic beads to ensure that the magnetic beads are used well. The magnetic beads produced by Aisen Biotechnology are of excellent quality and outstanding performance. They are very helpful in nucleic acid extraction. They can bind the target substance in a short time and avoid accidental injury to the human body. Customers in need are welcome to call for consultation.

We know that the rapid detection and sampling of human neocorona nucleic acid is mainly through nasopharyngeal swabs or oropharyngeal swabs. So how to do rapid detection of new crown nucleic acid for frozen food? In fact, the rapid detection of COVID-19 for food is similar to the rapid detection of human COVID-19. Next, let’s take a look at popular science for you:

1. Collection of seafood, fish and water samples

First open the gills of the fish sample, take a sampling swab, wipe 5-10 times on the gills, then put the sampling swab head into the collection tube containing the preservation solution, break the handle, and then seal it for inspection. ; Store the ice water sample of the fish, use a disposable plastic straw to suck 3-5ml into a 5ml preservation tube, and then seal it for inspection.

2. Frozen food for nucleic acid testing

For the rapid detection of COVID-19 on frozen foods, priority should be given to the collection of tissues with obvious diseased organs; secondly, aquatic products should be given priority to samples with internal organs and surrounding tissues; again, the same animal should be collected in the order of the sample types listed in the above table. The swab must be applied at the same time. No more than 3 samples can be collected from the same animal; finally, two samples are collected for each sample, one for testing and one for backup.

In addition to applying a swab on the surface of the food, the tissue also needs to be homogenized (homogenization is also called homogenization, which is a process of micronizing and homogenizing the dispersion in the suspension (or emulsion) system. This treatment simultaneously reduces the size of the dispersion and improves the uniformity of the dispersion), and then performs the normal rapid detection of new coronavirus nucleic acid, that is, reagent preparation, nucleic acid extraction, amplification detection, and issuance of reports.

3. Sampling of the surface of the object

Mainly cutting boards, knives, vegetables, meat, etc. First take a sampling swab, after soaking it in the preservation solution (if the surface of the object is wet, you can directly sample), wipe it horizontally and vertically on the surface of the object 5 times, and then put the sampling swab head into the collection tube containing the preservation solution. The handle is broken off, and then sealed and sent for inspection.

At present, most of the sporadic epidemics in many places are caused by cold chain foods, so the rapid detection of new crown nucleic acid in cold chain foods should also be attached great importance. It is necessary to strictly follow the sampling specifications and carefully sample the food and environment that may be contaminated. The rapid detection and sampling of new crown nucleic acids are mainly carried out for various types of frozen food, food packaging, related supplies and related staff, so as to achieve a comprehensive investigation, Leave no dead ends. Learn more about Nucleic Acid Extraction Kit.

There are many types of nucleic acid extraction kits，such as bacterial genomic DNA extraction kit ,whole blood genomic DNA nucleic acid extraction kit and etc. Today, we will mainly introduce the principle, use method and specific steps of the magnetic bead method nucleic acid extraction kit.

1. What is nucleic acid

Nucleic acids are widely present in all animals, plant cells, and microorganisms. Nucleic acids in organisms often combine with proteins to form nucleoproteins.

According to different chemical composition, nucleic acid can be divided into ribonucleic acid, referred to as RNA and deoxyribonucleic acid, referred to as DNA. DNA is the main material basis for storing, copying and transmitting genetic information. RNA plays an important role in the process of protein synthesis, among which transfer ribonucleic acid, tRNA for short. Plays the role of carrying and transferring activated amino acids; messenger ribonucleic acid, referred to as mRNA, is the template for protein synthesis. Ribosomal ribonucleic acid, rRNA for short, is the main place where cells synthesize proteins.

2. What is the magnetic bead method nucleic acid extraction kit

The magnetic bead method nucleic acid extraction kit uses a unique separation of magnetic beads and a buffer system to separate and purify high-quality genomic DNA from the sample. Special coated magnetic beads have a strong affinity for the target DNA under certain conditions. , And when the conditions change, the magnetic beads release the adsorbed DNA, which can achieve the purpose of rapid separation and purification of DNA. The whole process does not involve toxic reagents, it is safe, convenient, and the extracted DNA is of high purity. The genomic DNA (OD260-0D320/(0D280-0D320) purified by this kit is between 1.7 and 2.0, which can be applied to various downstream molecular biology experiments.

The magnetic bead method nucleic acid extraction kit uses a unique separation of magnetic beads and a buffer system to separate and purify high-quality genomic DNA from the sample. Special coated magnetic beads have a strong affinity for the target DNA under certain conditions. , And when the conditions change, the magnetic beads release the adsorbed DNA, which can achieve the purpose of rapid separation and purification of DNA. The whole process does not involve toxic reagents, it is safe, convenient, and the extracted DNA is of high purity. The genomic DNA (OD260-0D320/(0D280-0D320) purified by this kit is between 1.7 and 2.0, which can be applied to various downstream molecular biology experiments.

Accounting extraction kit: DNA extraction kit, RNA extraction kit

Composition: Lysis solution, binding solution, washing solution, eluent, biomagnetic beads, instructions

3. Use steps of magnetic bead method nucleic acid extraction kit:

1. Add Buffer C1, humic late adsorbent C2 and glass beads to the soil sample and vortex.
2. Add BufferC3 to lyse the cells
3. Add Buffer C4 to deform and precipitate protein
4. Gaoxin removes impurities such as large humic acid
5. Add BufferC 5. Ethanol to adjust the binding conditions
6. Transfer to a separation column and centrifuge to adsorb DNA
7. Add washing liquid to wash and remove impurities such as salt
8. Centrifuge for 1min to spin dry the base shield
9. Add TE and centrifuge for 1 min to elute DNA
10. High-quality DNA

The above is the relevant introduction of the magnetic bead method nucleic acid extraction kit, including the classification, composition, and specific use method steps of the nucleic acid extraction kit.