Site Visit: MLS BioDNA Ltd. - Report
The aim of the MLS BioDNA Ltd. is to use DNA from different organisms for tests these are some examples of tests that are performed at MLS BioDNA Ltd;
- paternity tests
- Bird sexing
- Test for Bacteria
- Pesticide testing for farmers.
DNA (Deoxyribonucleic acid) is found in all living things. Every cell of plants and animals has it’s own DNA.
Nearly every cell in a person’s body has the same DNA. Most of the DNA is located in the cell nucleus this is called nuclear DNA, but a small amount of DNA can also be found in the mitochondria where this is called mitochondrial DNA or mtDNA. The information in DNA is stored as a code made up of four chemical bases or nucleotides, these are: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T). The chemical bases (A, T) and (G, C) always stay in with each other you can never see a base (A, C) because this doesn’t exist. Human DNA consists of about 3 billion bases. Around 99% of these bases are the same in the same species.
The DNA of all the cells in the organism is all the same. If you take the DNA sample of a person from his hair, skin, blood, bones, teeth and body fluids.
DNA is made from Nucleotides, Carbon atoms and other substances. We all have if not the identical very similar DNA, 96% of the DNA of monkeys is identical to one another.
DNA is found in the chromosomes that are found in the Nucleus of all cells. In the case of humans we have 46 chromosomes and these are divided into two major groups, these are the Sex chromosomes and the Autozomal chromosomes.
Just like fingerprints every human has his own individual DNA. The only exception when there are two people that have identical DNA is when these are identical twins, but identical twins do not have the same fingerprint but his/her own individual fingerprint just like everyone else. Some recent studies shows that even identical twins may have some differences in there DNA.
The advantage of DNA testing over taking fingerprints is that to identify a person from his fingerprint you need a large surface area because if you don’t have enough surface area you would not be able to identify the fingerprint. While in DNA testing you only need a small sample of hair, skin, blood, bones or body fluids that you could later clone to make as much copies of the DNA as you would need. Another advantage of DNA testing is that DNA in bones and teeth especially stays the same for a very long period of time while fingerprints can be removed by wind or time.
DNA is used to identify body’s, for example in mass graves like those of the last war where soldiers killed hundreds of people and then dug one hole and threw everyone in one mass grave.
- paternity tests
- Bird sexing
- Test for Bacteria
- Pesticide testing for farmers.
DNA (Deoxyribonucleic acid) is found in all living things. Every cell of plants and animals has it’s own DNA.
Nearly every cell in a person’s body has the same DNA. Most of the DNA is located in the cell nucleus this is called nuclear DNA, but a small amount of DNA can also be found in the mitochondria where this is called mitochondrial DNA or mtDNA. The information in DNA is stored as a code made up of four chemical bases or nucleotides, these are: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T). The chemical bases (A, T) and (G, C) always stay in with each other you can never see a base (A, C) because this doesn’t exist. Human DNA consists of about 3 billion bases. Around 99% of these bases are the same in the same species.
The DNA of all the cells in the organism is all the same. If you take the DNA sample of a person from his hair, skin, blood, bones, teeth and body fluids.
DNA is made from Nucleotides, Carbon atoms and other substances. We all have if not the identical very similar DNA, 96% of the DNA of monkeys is identical to one another.
DNA is found in the chromosomes that are found in the Nucleus of all cells. In the case of humans we have 46 chromosomes and these are divided into two major groups, these are the Sex chromosomes and the Autozomal chromosomes.
Just like fingerprints every human has his own individual DNA. The only exception when there are two people that have identical DNA is when these are identical twins, but identical twins do not have the same fingerprint but his/her own individual fingerprint just like everyone else. Some recent studies shows that even identical twins may have some differences in there DNA.
The advantage of DNA testing over taking fingerprints is that to identify a person from his fingerprint you need a large surface area because if you don’t have enough surface area you would not be able to identify the fingerprint. While in DNA testing you only need a small sample of hair, skin, blood, bones or body fluids that you could later clone to make as much copies of the DNA as you would need. Another advantage of DNA testing is that DNA in bones and teeth especially stays the same for a very long period of time while fingerprints can be removed by wind or time.
DNA is used to identify body’s, for example in mass graves like those of the last war where soldiers killed hundreds of people and then dug one hole and threw everyone in one mass grave.
When investigators are at a crime scene they have to be careful because they would have very little DNA of the suspect and it is important that the crime scene is not disturbed. This is why the police put a perimeter where no one that isn’t involved in the crime can pass, because you can’t have people walking around leaving their DNA everywhere. The investigators also wear a white suit that covers all their skin and hair that can fall and contaminate the Suspect’s DNA with their own. They would also have a mask so that no spit or any other body fluids would contaminate the crime scene.
Extracting DNA involves; first collecting the DNA sample from the crime scene or where ever, then the cells of the sample are burst open to release the DNA in them, the DNA is then cleaned by separating the DNA from proteins and other cellular.
Extracting DNA involves; first collecting the DNA sample from the crime scene or where ever, then the cells of the sample are burst open to release the DNA in them, the DNA is then cleaned by separating the DNA from proteins and other cellular.
The Concentrated DNA is then multiplied for as much times as needed in the testing. The regions of the DNA are called loci. When there is too little DNA to work with the Poliminase Chain Reactor (PCR) is used to make copies of the DNA. The Poliminase Chain Reactor (PCR) only makes copies of certain regions of the DNA because not all the DNA is used for the testing.
Process:
- Denaturation: First the double helix of the DNA is broken down into only one strand. At the temperature of 95°C.
- Annealing: The primers which are pieces of DNA tell particular enzymes from where the region starts to where it would end. These enzymes would then stick to the single strand of DNA. This process is done at the temperature of 55°C to 60°C.
- Extraction: Now that the DNA is ready an enzyme calls more base pairs and copies of the DNA are made. This procedure takes place at around 72°C.
Process:
- Denaturation: First the double helix of the DNA is broken down into only one strand. At the temperature of 95°C.
- Annealing: The primers which are pieces of DNA tell particular enzymes from where the region starts to where it would end. These enzymes would then stick to the single strand of DNA. This process is done at the temperature of 55°C to 60°C.
- Extraction: Now that the DNA is ready an enzyme calls more base pairs and copies of the DNA are made. This procedure takes place at around 72°C.
After the PCR has done its job the DNA has to be analyzed further. This is done by placing the DNA in a jelly like substance caked Agarose. This is a filter that sorts the DNA according to its size. This process is called Gel electrophoresis. When conducting Gel electrophoresis the jelly like substance containing the DNA are placed on a screen where Ultra Violet radiation (UV light) in given out. The bands of the DNA are colored with Atidum Bromide which under Ultra Violet radiation (UV light) lights up.
This procedure of extracting the DNA and profiling has many different uses. For example at the MLS BioDNA testing labs this procedure is used in:
· Paternity Testing:
In a paternity test where there is a known offspring and an unknown father or vice versa, for example two men think that they are the fathers of the same offspring. First the DNA samples from the two possible fathers, the mother and from the offspring are taken. A specific enzyme that cuts the DNA at specific sequences is inserted in the DNA samples. The DNA is now placed in a type of gel that separates the DNA by gel electrophoresis.
A DNA paternity test can be ordered by court. The epithelial cells from the inside of the cheeks by the use of a swab. These epithelial cells contain all the DNA sequences necessary to confirm paternity and maternity.
· Bird Sexing:
This procedure is also used in bird sexing (to find out if the bird is male or female). In Bird sexing capillary extrapolises is used instead of the gel electrophoresis.
· S.T.I.’s
This procedure is also used to test for the presence of S.T.I.’s. When testing for S.T.I.’s a sample of urine is taken into the lab and the same procedure of Annealing, Denaturation and Extraction.
· Paternity Testing:
In a paternity test where there is a known offspring and an unknown father or vice versa, for example two men think that they are the fathers of the same offspring. First the DNA samples from the two possible fathers, the mother and from the offspring are taken. A specific enzyme that cuts the DNA at specific sequences is inserted in the DNA samples. The DNA is now placed in a type of gel that separates the DNA by gel electrophoresis.
A DNA paternity test can be ordered by court. The epithelial cells from the inside of the cheeks by the use of a swab. These epithelial cells contain all the DNA sequences necessary to confirm paternity and maternity.
· Bird Sexing:
This procedure is also used in bird sexing (to find out if the bird is male or female). In Bird sexing capillary extrapolises is used instead of the gel electrophoresis.
· S.T.I.’s
This procedure is also used to test for the presence of S.T.I.’s. When testing for S.T.I.’s a sample of urine is taken into the lab and the same procedure of Annealing, Denaturation and Extraction.
G.C.M.S.
Gas Chromatography and Mass Spectrometry (GCMS), this is an optical device which is used to separate a mixture and identifies them according to their mass. First the Gas Chromatographer separates the mixture then the separated mixture goes through a column in the Mass Spectrometer, the Mass Spectrometer detects the mass of the gas and looks for the name of the sample in its database. This technique can only be used with volatile liquids or gases. An example of when the (G.C.M.S.) is when you need to test if a person is under the affect of alcohol. This can be used because alcohol is very volatile. First a blood test or later on a urine test is taken and placed in the (G.C.). Then the (M.S.) breaks down and fragments the molecule of the chemical to see it’s mass. The substance that would be detected would be methanol because it is very small and only has 1 carbon atom.
Gas Chromatography and Mass Spectrometry (GCMS), this is an optical device which is used to separate a mixture and identifies them according to their mass. First the Gas Chromatographer separates the mixture then the separated mixture goes through a column in the Mass Spectrometer, the Mass Spectrometer detects the mass of the gas and looks for the name of the sample in its database. This technique can only be used with volatile liquids or gases. An example of when the (G.C.M.S.) is when you need to test if a person is under the affect of alcohol. This can be used because alcohol is very volatile. First a blood test or later on a urine test is taken and placed in the (G.C.). Then the (M.S.) breaks down and fragments the molecule of the chemical to see it’s mass. The substance that would be detected would be methanol because it is very small and only has 1 carbon atom.
Extracting DNA from a Banana:
To extract DNA from a Banana or nearly any other fruit you would need some common household items. You would need some clothing detergent, Surgical spirit, banana or other fruit, table spoon, strainer, plate, table salt and a clean glass of water with the smallest diameter you could find.
1. First place half a banana in a plate and mash it up with water and some table salt.
2. The solution produced is passed through a strainer so that only the liquid would pass through.
3. The mix was placed in a glass and one table spoon of detergent was added.
4. After ten minutes of the detergent and banana solution where added together the liquid was placed in a narrow glass or test tube. Only 1/3 of the glass or test tube was filled.
5. Some surgical spirit was added to the mixture.
6. Whitish strands would start to appear just below the layer of surgical spirit.
7. By the means of cotton bud the strands of DNA where collected.
In this experiment the detergent breaks down the cells and releases the DNA and the surgical spirit precipitates the DNA.
To extract DNA from a Banana or nearly any other fruit you would need some common household items. You would need some clothing detergent, Surgical spirit, banana or other fruit, table spoon, strainer, plate, table salt and a clean glass of water with the smallest diameter you could find.
1. First place half a banana in a plate and mash it up with water and some table salt.
2. The solution produced is passed through a strainer so that only the liquid would pass through.
3. The mix was placed in a glass and one table spoon of detergent was added.
4. After ten minutes of the detergent and banana solution where added together the liquid was placed in a narrow glass or test tube. Only 1/3 of the glass or test tube was filled.
5. Some surgical spirit was added to the mixture.
6. Whitish strands would start to appear just below the layer of surgical spirit.
7. By the means of cotton bud the strands of DNA where collected.
In this experiment the detergent breaks down the cells and releases the DNA and the surgical spirit precipitates the DNA.
Titrations:
A titration is an old technique which is still used in the present day because there is no electronic way to do this. By conducting a titration you would find the number of moles per dm³. To do this procedure you need to make a standard solution or use a reliable indicator.
To do a titration you would need a burette, (pipette, pipette filler)*, funnel, retort stand, a conical flask, standard solution or indicator, the substance needed for testing and some distilled water.
* These are only needed if a standard solution is being used.
It is important that before starting the titration all the glassware is cleaned with tap distilled and the solution that it is going to come in contact with. The burette was filled to the zero mark with the solution that is going to be and a conical flask was filled with the indicator needed. The solution tested would be let down slowly until a clear colour change is noted. The titration is repeated until two values are only 0.1 apart from each other.
To do a titration you would need a burette, (pipette, pipette filler)*, funnel, retort stand, a conical flask, standard solution or indicator, the substance needed for testing and some distilled water.
* These are only needed if a standard solution is being used.
It is important that before starting the titration all the glassware is cleaned with tap distilled and the solution that it is going to come in contact with. The burette was filled to the zero mark with the solution that is going to be and a conical flask was filled with the indicator needed. The solution tested would be let down slowly until a clear colour change is noted. The titration is repeated until two values are only 0.1 apart from each other.
Preparing Distilled water:
The procedure of preparing Distilled water is very easy. It is only simple distillation. The water is placed in a container and heated from below by using a Bunsen burner or an electrical device that has a heating element. The water is heated at the temperature of 100°C because at this temperature only pure water would evaporate because impurities would evaporate at a higher temperature. If the water is going to be separated from a solution that evaporates below the temperature of 100°C like ethanol the first amount of liquid collected is discarded and at the temperature of 100°C a new container is placed and distilled water is collected.
The procedure of preparing Distilled water is very easy. It is only simple distillation. The water is placed in a container and heated from below by using a Bunsen burner or an electrical device that has a heating element. The water is heated at the temperature of 100°C because at this temperature only pure water would evaporate because impurities would evaporate at a higher temperature. If the water is going to be separated from a solution that evaporates below the temperature of 100°C like ethanol the first amount of liquid collected is discarded and at the temperature of 100°C a new container is placed and distilled water is collected.
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