Applications of Electrophoresis in DNA Protein Separation and Clinical Diagnostics
Electrophoresis is known as the movement of the dispersed or colloidal particles that are suspended in a given fluid because of their interactions with the electric field that is uniform partially. The electrophoresis process of the positively charged particles called cations is often referred to as cataphoresis. On the other hand, the electrophoresis of the negatively charged particles called anions is referred to as anaphoresis. It is caused due to the presence of an interface that is charged and lies between the surface of the particle and the surrounding fluid. It makes for the basis for different analytical techniques that are used in Chemistry to separate the molecules according to their charges, size, or binding affinity.
The electrophoresis process is also used in laboratories for separating the macromolecules depending on their size. This technique includes the application of a negative charge so that the proteins would move towards the positive charge. Electrophoresis is also widely used in the analysis of DNA, RNA and different proteins. We will discuss the electrophoresis uses and the application of electrophoresis in chemistry in this article.
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Application of Electrophoresis in DNA Analysis and DNA Fragmentation
Amongst the most important applications of the process of electrophoresis is in the analysis of DNA analysis the studying of DNA fragments. DNA is known for the negative charge consistency that it holds and it is affected due to the presence of the electrical current. When pressure is exerted on it by the electric field, DNA starts to break down into small and large fragments. This happens because different kinds of DNA fragments get affected by the current on different scales. A test medium like an agarose gel or an acrylamide gel is used for freezing the separated fragments of a particular DNA strand. The electric field is then removed and the study of these fragments is carried out.
Application of Electrophoresis in Protein Detection
A type of electrophoresis known as immunoelectrophoresis is common and used for analysing several kinds of proteins’ existence and how they behave chemically in different environments. When irregular molecules of proteins are formed they get triggered because of various medical conditions like multiple sclerosis, kidney failures and even different kinds of cancers. The irregular proteins are detected by the method of electrophoresis on the urine or blood samples and frequently checking its results for any kind of deviations from standard forms and amounts of the protein. Immunoelectrophoresis is also used for the detection of specific proteins which are called immunoglobulins.
Application of Electrophoresis for Testing Antibodies
Electrophoresis plays a variety of essential functions when it comes to the testing of antibiotics.
The most common applications of the process of electrophoresis in this field are the testing of antibiotics to check their purity. Electrophoresis is used in a solution that consists of the antibiotic to be tested in the form of a paper strip. This strip is impregnated with a capillary or the antibiotic which is filled with the drug.
Electrophoresis is also used for determining the strength of the antibiotic having a vital importance in regards to administering the exact dosages. Also, the antibiotic research field has a common ground along with the genetic testing field. Hence, electrophoresis also helps in discovering the genes which tend to indicate the resistance to a specific kind of antibiotics.
Factors affecting Electrophoresis
Below are the factors that affect the process of electrophoresis.
Electric Field
The electric field is one of the major factors affecting the process of electrophoresis. The movement of ions in electrophoresis depends on the current, resistance, and voltage in the electric field.
During electrophoresis, the voltage of the electric field affects the travel time of the molecules being separated. With higher voltage, the DNA will be able to travel through the gel much faster. However, excessively high voltages can melt the gel or even cause distortion of DNA bands.
The distance travelled by the ions in electrophoresis is directly proportional to the time and current. Since the current is conducted between electrodes, the increase in voltage leads to an increase in the number of charges towards each electrode.
Resistance of electrophoresis depends on the thickness of the gel, size, buffer conductivity, temperature, and the amount of buffer. It usually decreases with an increase in the temperature. The amount of resistance will determine whether the circuit is a bad conductor or a good one.
Sample
The size, shape, and charge of the sample, which is being separated during electrophoresis, affect its migration rate. With an increase in the charge, the rate of migration will also increase. Moreover, the rate of migration is also affected by the change in the size of the molecule and the shape of the sample. It is inversely proportional to the size and shape of the sample.
Buffer
The migration rate of the compound is affected by the buffer, which stabilises the pH levels of the supporting medium. Some of the most commonly used buffers for the electrophoresis process are EDTA, formate, Tris, citrate, barbitone acetate, and pyridine. The migration of the sample used can be affected if the buffer binds to the molecules, which is why it should never bind to them.
The proportion of the current carried by this buffer will increase while the current carried by the sample being separated will decrease. At low ionic strength, the proportion of the current carried by the buffer will decrease and the one carried by the sample will increase.
Heat generation is oftentimes a problem that occurs during electrophoresis. The heat generated during electrophoresis changes the density and viscosity of the electrophoretic media. It can also damage the equipment by melting the plastics, cracking the glass plates, warping, etc.
In case the conductivity of the supporting medium is high, the process of electrophoresis becomes more difficult. It is because solutions with high conductivity lead to a lower field strength per current and the heat load on the system increases.
Supporting Medium
The supporting medium used in electrophoresis can affect the migration rate of the sample. Usually, the inert medium is preferred during the process of electrophoresis. This medium, however, can cause molecular sieving, absorption, or electro-osmosis that can affect electrophoresis. Absorption can cause tailing of the sample, which causes a disruption in the movement of the sample. It also reduces the rate and resolution of the separation during electrophoresis.
FAQs on Application of Electrophoresis in Analytical and Biochemical Chemistry
1. What is electrophoresis in chemistry?
Electrophoresis is a separation technique that uses an electric field to move and separate charged particles in a medium based on their size and charge. In this method, molecules such as proteins, DNA, or ions migrate toward the oppositely charged electrode when voltage is applied.
- Positively charged ions move toward the cathode (–).
- Negatively charged ions move toward the anode (+).
- Separation depends on charge, size, and shape of the particles.
2. What are the main applications of electrophoresis?
The main applications of electrophoresis include the separation and analysis of DNA, RNA, proteins, and ions in chemistry and biology. Common applications are:
- DNA fingerprinting in forensic science.
- Analysis of proteins in blood serum.
- Determination of molecular weight of biomolecules.
- Purification of nucleic acids and proteins.
- Clinical diagnosis of genetic disorders.
3. How does electrophoresis work?
Electrophoresis works by applying an electric field that causes charged particles to migrate through a supporting medium. The basic steps are:
- A sample is placed in a gel or buffer medium.
- An electric potential difference is applied across electrodes.
- Charged molecules move toward the oppositely charged electrode.
- Smaller or highly charged particles migrate faster.
4. What are the different types of electrophoresis?
The main types of electrophoresis include gel electrophoresis, capillary electrophoresis, and paper electrophoresis. Important types are:
- Agarose gel electrophoresis – mainly for DNA and RNA.
- Polyacrylamide gel electrophoresis (PAGE) – for proteins and small DNA fragments.
- SDS-PAGE – separates proteins by molecular mass.
- Capillary electrophoresis – high-resolution separation in narrow tubes.
- Paper electrophoresis – early method for separating amino acids.
5. What is the application of electrophoresis in DNA analysis?
Electrophoresis is used in DNA analysis to separate DNA fragments based on their size for identification and comparison. In agarose gel electrophoresis:
- DNA fragments, which are negatively charged due to phosphate groups, move toward the anode (+).
- Smaller fragments travel faster through the gel pores.
- Separated bands are visualized using stains.
6. How is electrophoresis used in protein separation?
Electrophoresis separates proteins based on their charge and molecular mass, commonly using SDS-PAGE. In SDS-PAGE:
- Proteins are treated with sodium dodecyl sulfate (SDS), giving them a uniform negative charge.
- They migrate toward the anode (+) under an electric field.
- Separation occurs primarily according to molecular weight, with smaller proteins moving faster.
7. Why is electrophoresis important in forensic science?
Electrophoresis is important in forensic science because it enables DNA profiling for individual identification. In forensic analysis:
- DNA from crime scenes is amplified using PCR.
- Fragments are separated by gel or capillary electrophoresis.
- The resulting band pattern is compared with suspects or databases.
8. What factors affect the rate of electrophoresis?
The rate of electrophoresis depends on the charge, size, electric field strength, and medium properties. Key factors include:
- Magnitude of charge – higher charge increases migration speed.
- Particle size – smaller particles move faster.
- Electric field strength – higher voltage increases migration rate.
- Viscosity and pore size of the medium.
- Buffer pH, which affects ionization and charge.
9. What is the difference between electrophoresis and electroosmosis?
Electrophoresis is the movement of charged particles in an electric field, whereas electroosmosis is the movement of the liquid medium itself under an electric field. The key differences are:
- Electrophoresis: migration of solute particles (e.g., DNA, proteins).
- Electroosmosis: bulk flow of solvent due to charged surface interaction.
- Electrophoresis depends on particle charge; electroosmosis depends on surface charge of the medium.
10. Can you give an example of electrophoresis in clinical diagnosis?
An example of electrophoresis in clinical diagnosis is serum protein electrophoresis (SPEP), used to detect abnormal protein levels in blood. In SPEP:
- Blood serum proteins are separated into albumin and globulin fractions.
- Abnormal band patterns indicate diseases such as multiple myeloma.
- The technique helps in monitoring liver disease and immune disorders.
