Tag: DNA analysis

Introduction

Protein, DNA, and RNA can all be separated from one another using an external electric field and this laboratory technique. As the gel or matrix employed includes a given size and enables just a particular molecule, the separation of molecules occurs on the basis of charge and size. Only very small particles, such as atoms or ions, may fit through the pores. By doing so, molecular separation is possible.

When electricity flows, ions can migrate to various poles. In electrophoresis, the movement of anions is known as anaphoresis and that of cations is known as cataphoresis. When a current is applied, proteins migrate to the positive poles, where they may be more easily separated.

What is Electrophoresis?

Electrophoresis is the process by which a current drives charged molecules to separate poles. Molecules with a positive charge will go away from the cathode and towards the anode. Negatively charged molecules will seek out a cathode, which is the opposite pole of an electrode.

As proteins and nucleic acids are negatively charged, they gravitate towards the cathode. Because to its association with electricity and ion motion, electro kinetics is another name for this field. Capillary electrophoresis and slab electrophoresis are the two most common forms. Gel and paper electrophoresis are examples of capillary electrophoresis, while Iso-electro focusing and Zone electrophoresis are examples of slab electrophoresis.

Gel Electrophoresis

Applications of Electrophoresis

Electrophoresis is applied in many fields because of its feasibility and inexpensive mode. Some of its applications are,

DNA Fragmentation and DNA Analysis 

Gel electrophoresis is the process used for the separation of DNA fragments based on their size. The approximate size of DNA is also obtained in this process

Protein Detection

Gel electrophoresis is again employed for the detection of proteins. Proteins have higher migratory power and that is employed for its detection. By the application of external current, the charged particles of proteins will migrate towards their opposite electrodes. As protein is negatively charged it will migrate towards the cathode. It can also use the liquid matrix for the separation. The majority of protein applications can be achieved by the use of this process. They include purity determination and purification of proteins.

Testing of Antibodies

Immune electrophoresis detects antibodies. Antibodies on a gel do it. blood test. If the sample contains the antigen, an antigen-antibody complex will form. IgA, IgM, etc. are easily diagnosed.

Factors affecting the Process of Electrophoresis

Some factors can substantially affect the process of electrophoresis. They are,

Electric Field: Electric field is responsible for the movement of charged particles towards the oppositely charged electrodes. So it plays an important role in the process of electrophoresis.

 Sample features/details: The features of the sample such as size, shape, and charge have an important role since it is a size-based and charge-based separation. If the charge of a molecule is high the rate of migration will also high. But if the size increases the rate will decrease.

Buffer: For stabilizing the pH of the medium buffer solution is necessary the use of zwitterionic buffers will be much better.

Supporting Medium: It plays a predominant role since the medium can alter the rate of migration by having some adsorption property. Electro osmosis will also result due to some mediums. So selection of a proper support medium will increase the rate of migration.

 How does gel electrophoresis work?

Gel electrophoresis is a type of electrophoresis in which charged particles or ions of biological molecules can be separated by the application of an external field. They move through a gel hence the name gel electrophoresis is used. And its movement is called migration. And the migration of ions is to oppositely charged electrodes. The electric current for this process is applied across the gel. The gel acts as a sieve since it contains small pores that can only allow small-sized molecules. DNA fragments are distinguished using this electrophoresis. And DNA is a negatively charged species so it will migrate to the rds cathode.

What is agarose gel electrophoresis?

One of agar’s main components is a matrix for the electric current-based synthesis of macromolecules. Agarose gel is commonly employed as a matrix in the separation of DNA and big protein molecules because it is simple to cast, has a good pore size, and has a good gel strength. It has several charged groups and aids in water movement in the opposite direction of DNA movement towards the anode. A larger concentration of agarose gel is required for the separation of tiny molecules.

What are the advantages of electrophoresis?

The advantages of electrophoresis are,

• The mode of operation of this technique is easy.
• Short time is only needed.
• Needs only a low sample.
• The consumption of electrolytes during the process is low.
• Can be used as an analytical tool and also as a synthesis tool.
• The bulk amount of proteins shall be separated.
• Inexpensive apparatus.

Summary

Samples are separated by size and charge using electrophoresis. It is medium dependent, and the various forms it takes are defined by the medium used. Several types of electrophoresis in tubes and capillaries. Gel electrophoresis, zone electrophoresis, etc., are also included. Gel electrophoresis stands out because it is used to separate proteins, DNA, RNA, and other biomolecules. Gels aid the separation process since only molecules of a certain size may pass through them; if an electric field is applied, the molecules in question will align themselves into a distinct band, making them easy to identify. The supercoiled structure of agarose gel makes it a viable alternative matrix. Electrophoresis has various benefits due to being a cheap and efficient method.

 Frequently Asked Questions

1. What is the difference between SDS-PAGE and Native PAGE?

Ans. SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) is a technique used to separate proteins based on their size and charge. Native PAGE (polyacrylamide gel electrophoresis) is a technique used to separate proteins based on their size and shape. 

2. What is Capillary Electrophoretic Enzyme Assay?

Ans. Applications of the analytical separative technique known as capillary electrophoresis (CE) extend far beyond the realm of enzymatic research.

In an open capillary, the substrate and the product are separated by size and charge in an electric field.

3. What is the haemoglobin electrophoresis test?

Ans: It is an electrophoresis test that can be used to the identification of the amount of haemoglobin present in the sample blood.

Introduction

When it comes to preventing and solving crimes, forensic science is invaluable. It’s utilized as evidence in court to help determine a defendant’s guilt or innocence and to help identify potential perpetrators. From the time the first fingerprint was used to identify a suspect in a murder in the 19th century, forensic science has played a role in the resolution of homicides. A lot of different tools and methods have been added to the field since then. DNA analysis, fingerprinting, ballistics, and toxicology are just a few of the methods used by modern forensic scientists to examine physical evidence.

What is Forensic Chemistry?

Forensic Chemistry would seem to be a branch of chemical sciences that thus combines chemical as well as toxicological techniques to detect unknown factors in such a crime scene. The tests have been performed by forensic chemists, who are experts in their field. To achieve goals, these professionals adopt a variety of tactics as well as techniques. 

What Does a Forensic Chemist do?

It is the job of a forensic chemist, who typically works in such a lab, to analyze evidence found at a crime scene. Investigators are hired by both the government and commercial firms. The samples are collected by the detectives or investigators and then sent to the forensic chemist for analysis. They need to be well-versed in both Organic and Particle Physics. Scientists utilize organic chemistry to analyze body samples for DNA and toxicants.

Role of a Forensic Chemist

A Forensic Chemist’s primary responsibility is to gather substances identified at a crime site and further analyze them to determine how they correlate to the crime. Forensic chemists combine chemistry, physics, as well as biology to discover compounds that could aid in the prosecution of a crime. Their job involves tracing chemicals, narcotics, as well as other substances, and even using methods such as spectroscopy, and chromatography, with the usage of infrared as well as ultraviolet lamps to locate evidence. Most of the samples recovered at crime scenes are retained, but if necessary, testing is performed on them.

Methods used in Forensic Chemistry

Chromatography: Some compounds are unknown but must be disassembled into individual elements for study. Chromatography is indeed the technique of separating the elements of any mixture. The mixture would be first dispersed in a material termed the mobile phase. The mobile phase can then be mixed with the second material, termed the stationary phase, as well as the mixture, which has been separated into two or more substances. It is widely used in investigations involving poisoning, explosives, and so on.

Spectroscopy: It is a method of detecting evidence used within forensic chemistry. This is primarily dependent on both absorptions as well as the emission of light or even radiation by materials as the wavelength of such radiation changes. This even relates to the collisions of electrons, protons, as well as ions.  This procedure is often performed to assess blood toxicity.

Spectroscopy Mechanism

Why a Forensic Chemistry Degree?

After completing their degree, forensic chemists could pursue a variety of careers, including:

• Chemical analyst
• Scientist in Biomedicine
• Investigator at a crime site
• Detective
• Forensic Scientist
• Technician in a scientific laboratory
• Toxicologist
• Secondary school instructor
• Computer forensic specialist
• Officer of the Border Force
• Science professor

Tips to Prepare for Forensic Chemistry

1. Take courses in chemistry, biology, and physics: A strong foundation in these three sciences is essential for success in forensic chemistry.
2. Develop strong laboratory skills: Forensic chemists must be able to accurately and precisely measure, analyze, and interpret data. 
3. Become familiar with the legal system: Understanding the legal system and the role of forensic chemists in it is essential for success in the field. 
4. Learn about the different types of evidence: Forensic chemists must be familiar with the different types of evidence that can be used in criminal investigations. 
5. Develop strong problem-solving skills: Forensic chemists must be able to think critically and solve complex problems. 
6. Become familiar with the latest technology: Forensic chemists must be able to use the latest technology to analyze evidence. 
7. Develop strong communication skills: Forensic chemists must be able to effectively communicate their findings to other professionals. 
8. Get experience in the field: Internships and volunteer opportunities can provide valuable experience in the field of forensic chemistry.

Summary

Forensic Chemistry is a subfield of forensic science. This is an example of chemists’ helping police with their investigations. It really is that important to the study as a whole. A Forensic Chemist is an expert in detecting and analysing substances found at a crime scene using a variety of Forensic Chemistry techniques. If they come upon anything useful, they’ll report it to the detective. Forensic science appears to rely primarily on spectroscopy and chromatography as its primary methods.

Frequently Asked Questions

1. What type of chemical is utilized in fingerprinting?

To expose or even gather fingerprints, forensics experts use four basic chemicals: silver nitrate, ninhydrin, cyanoacrylate, as well as iodine. Certain chemicals react to elements within fingerprint, including oil as well as perspiration, changing the colour of the print and therefore, allowing experts to see it better.

2. What methods do forensic scientists use to examine drugs?

In most cases, forensic drug testing is conducted in 2 stages: screening as well as confirmation. When drugs are found via screening, such as spot test kits, samples have been collected and then forwarded to labs for confirmation testing.

3.Who is considered the father of forensic chemistry?

The “Father of Toxicology,” Mathieu Joseph Bonaventure Orfila (1787-1853), was the very first prominent nineteenth-century pioneer of forensic science. He tried to form chemical analysis, a common aspect of forensic medicine, but also researched asphyxiation, body decomposition, as well as exhumation.