Sciencedoze: Science, Education and Technology

What is Hemoglobin? Hemoglobin is an iron-containing globular protein present in red blood cells (RBCs). They impart a red color to the blood and help in transporting oxygen from the lungs to different parts of the body. A healthy individual has about 12-20 g of hemoglobin in every 100 ml of blood. Hemoglobin is a tetrameric protein that contains the heme prosthetic group attached to each subunit. Lackness of Hemoglobin in the blood can cause anemia. Hemoglobin is made up of four amino acid chains and each of these chains contains heme. This is the compound that contains iron. The heme molecule forms strong covalent bonds with a globular protein, primarily through the nitrogen atoms of the imidazole ring located beneath the porphyrin ring. Types of Hemoglobin After Birth Hemoglobin A It accounts for 95-98% of Hemoglobin in adults. It consists of two alpha and two beta polypeptide chains, which together form the complete structure. Hemoglobin A2 It accounts for 2-3% of Hemoglobin pr...

What is Blood? Blood is a body fluid that is dark brown to red. It contains four components that are plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets. Blood is essential for life as it delivers essential substances like oxygen and nutrients to various body cells. It also helps to fight infection and also regulate the pH of the body. An average human adult contains approx 5 liters of blood which contributes to 8% of the total body weight. The blood in the body contains 55% plasma and 45% blood cells. Composition of Blood  1. Plasma The liquid component of blood is called plasma. It is yellowish and made up of mainly water, but it also contains proteins, sugars, hormones, and salts. Plasma helps in the transportation of blood cells throughout the body with water and nutrients. 2. Red Blood Cells (RBCs) Red blood cells (RBCs) account for approximately 40-45% of blood volume and appear bright red due to their hemoglobin content. Hemoglobin enables RBCs to ...

What is DNA Quantitation? DNA quantitation is a process in which the quantity of DNA extracted is estimated. It is important to know the quantity of DNA because it helps in DNA purifying and performing PCR. Aiding too little DNA will result in a profile that is difficult to analyze. Methods of DNA Purification 1. Spectrophotometry Spectrophotometry techniques like UV absorbance can be used in DNA quantitation. DNA absorbs light maximally at 260 nm . This helps in estimating the amount of DNA by measuring the absorbance of light at wavelengths ranging from 220 nm to 300 nm. In this method, the DNA sample is placed in a quartz cuvette and the absorbance is measured against the standard sample. Moreover, fluorescent dyes (Ethidium Bromide) can also be used for DNA quantization using spectrometry. These dyes interact with double-standard DNA and produce fluorescence which is detected by spectrophotometer. 2. Agorose Gel electrophoresis This method is used for the separation of DNA fragme...

Whats is DNA Purification? DNA purification is followed just after the DNA extraction as the DNA cell concentrate will also contain protein and RNA. The purification is done to remove these contaminants. The highly purified DNA sample increases the efficiency of the experiment and the chances of a false positive result are also reduced. Further, the purified DNA can be amplified using the PCR technique. Methods for DNA Purification 1. Treatment with Alcohol Alcohols like Methanol, Ethanol, and isopropanol can be used in DNA purification as well as DNA precipitation. Once the DNA is precipitated, it is washed with 1 ml of alcohol and then the mixture is vortexed gently until the clear DNA pellet is observed. After this, the sample undergoes high-speed centrifugation. The centrifugal force resulted in the separation of debris and other contaminants from the DNA at this location. 2. Gel filtration This is a type of chromatography technique that uses molecular sieving properties of porous...

What is DNA Extraction? DNA Extraction is a process of taking out DNA from a cell by breaking the cell membrane and Nuclear membrane with the help of chemical, enzyme, and physical disruptions. The first DNA isolation was done in 1869 by Friedrich Miescher.   Common sources of DNA isolation are whole blood, hair, semen, saliva, buccal (cheek) swabs, urine, and other important biological fluids. DNA isolation helps a forensic expert to link a suspect from a crime scene. Steps involved in DNA isolation 1. Cell and tissue disruption Cell and tissue disruption is done using an enzyme known as Proteinase K. Tissues can also be disrupted using boiling and alkali agents. Bones and teeth are frozen in liquid nitrogen and then ground to a fine powder. 2. Lysis of membranes and other organelles Detergents like Sodium dodecyl sulfate (SDS) and Sarkosyl are used for the lysis of membranes in which DNA is released from nuclei and mitochondria. A buffer like Tris-HCl is used to maintain the p...

What is Biological Warfare? Biological warfare is the use of various biological agents like bacteria, viruses, insects, and fungi to kill or harm some humans. A biological attack can result in a large number of causalities and can disrupt the economy and infrastructure of the enemy country. A famous example of biological warfare is the use of bioagents in world war 1 that causes anthrax and glanders infection. To reduce the proliferation of biological warfare agents, the Biological Weapons Convention (BWC) was signed in 1972. This international treaty prohibits the development, production, acquisition, transfer, stockpiling, and use of biological weapons. Its aim is to ensure the peaceful use of biological sciences and prevent the misuse of biological agents for harmful purposes. Categories of Biological agent The CDC of the united states divided various biological agents that are used in biological warfare into the following categories: 1. Category A These weapons can have devastati...

Agarose Gel Electrophoresis Agarose gel electrophoresis helps in the separation of DNA fragments based on their speed of movement in Agarose gel towards the anode. In this technique, the DNA sample is poured into the wells on the Agarose gel which are made using a comb. Also, a fluorescent dye called Ethidium is added to the sample DNA prior to electrophoresis to increase the viscosity of the sample which will prevent it from floating out of the wells. The migration of the sample can be seen through the gel. A DNA marker (Also called DNA ladder) is also loaded into the first well of the gel. The fragments in the markers are of known length which will be compared with the size of DNA fragments of sample DNA. Now the electric current is turned on so that the negatively charged DNA molecules move toward the positively charged anode. The shorter lengths of DNA will move faster than the longer lengths of DNA in the gel. The electric current is kept on till DNA fragments move far enoug...

What is Animal Cell?  The animal cell is a type of eukaryotic cell having a nucleus at the center that contains the DNA and the cell is covered with a selective membrane called cell or plasma membrane that only allows the passage of some specific materials. A cell carries out all the processes of the body which include producing energy and storing it, making proteins which are molecules that have roles in metabolism, transportation of other molecules, and DNA replication. Different organelles of Animal cell and their function 1. Cell/plasma membrane A cell membrane is a semipermeable selectively permeable membrane that regulates the entry and exit of nutrients, food, and other entities of the cell. It allows only specific material to pass through it. The cell membrane also separates the organelles of the cell from the outside medium. Thus, protecting the cell from its surroundings. 2. Nucleus The nucleus is present at the center of the cell occupying nearly 10% of the space. A...