Seth Miller asked:




DNA or Deoxyribonucleic acid is the genetic material present in the cells of a living being. Every nucleated cell has 46 chromosomes, apart from the sperm cells from the man and the egg of the woman that only contain 23 chromosomes. Forty- six chromosomes are essential to create a human being at the time of conception. Thus at conception, every human being receives half a DNA from the biological father and the other half DNA from the biological mother. Usually, DNA testing is conducted to verify the paternity and ancestry of a person. DNA testing is also an important tool used in tracking down criminals. It is used to create a portrait of criminal suspects.

A variety of DNA testing protocols are used worldwide. They analyze a small portion of DNA that varies from person to person. Tests are conducted using molecular methods such as a polymerase chain reaction or with DNA arrays and DNA chips.

DNA testing is a very simple and affordable process. Various stages are involved in DNA testing. It is necessary to obtain the DNA samples that have to be verified. DNA testing requires only a few drops of blood or cheek cell specimens obtained by rubbing the inside of the mouth with a swab. Most companies provide a free kit to collect these samples at home. The sample is then sent to a laboratory for analysis. The samples undergo a controlled procedure that includes extraction of cells from the swabs and purification and harvest of the DNA material found in the cells. The target regions of the DNA sample are copied, and the different target regions of DNA are separated from each other. The results of the DNA tests are then analyzed. Generally, the entire process is repeated to confirm the result, and a conclusive report is made after the confirmation of results.

The stages involved in DNA testing largely depend on the objectives behind the test. In most cases, self-sampling is sufficient to carry out DNA tests.

Genealogy: Uncovering Your Ancestry

J.J. Yong asked:




In US alone, more than half population is either overweight or obese. The statistic is alarming as obesity is associated with many chronic diseases including cardiovascular disorders, diabetes and others. It's a need to identify genes that have prominent influences on obesity.

INSIG2 gene induced by insulin would inhibit the fatty acid and cholesterol synthesis. People with a sequence variation near the gene would exhibit more fat accumulation, as the normal functional gene could not complete its potential.

In three rare diseases of severe fat malabsorption, chylomicron retention disease (CMRD), Anderson disease and CMRD with Marinesco Sjogren syndrome, the Sar1b protein required for all dietary fat absorption could not work normally because of genetic mutation.

Gene variant FTO that is susceptible to type 2 diabetes can be found among over half of European population who is linked with obesity causes. If a person with two copies of FTO variant is likely to weigh 3 kilos more than a normal person, and person with only one copy there are more likely to weigh 1.2 kilos more.

The human lipin gene might be a candidate for obesity was excess levels in fat tissue or skeletal muscle will promote the condition. Deficiency in lipin levels would prevent normal development of mature fat cells.

Another mutant gene, ENPP1 which presents in 20% Caucasians and 50% of black people, will block insulin from binding in pancreas and the brain. Thus, the insulin resistance will store excess glucose production from liver as layers of fat and diminish insulin secretion that will lead to increased risk of type 2 diabetes.

GAD2, a gene found on chromosome 10 can speed up the production of a chemical transmitter in the brain, GABA, which stimulates appetite. One form of the gene appeared to protect some people against obesity, while another form increased the risk of the disorder.

About 20 genes maybe involved in causing common obesity, but genetics alone cannot fully account for a worldwide obesity trend in recent decades.

The Name Book: Over 10,000 Names, Their Meanings, Origins, and Spritual Significance

Rich Fuller asked:




There are two main methods which can be used for paternity DNA testing, namely, PCR (Polymerase Chain Reaction) and RFLP (Restriction Fragment Length Polymorphism). In this article we are going to be looking at these two methods, what the difference is and how they work.

Polymerase Chain Reaction testing usually involves taking a swab from the inner cheek for DNA samples. It is a faster test than RFLP and usually looks at between six and nine loci on the DNA. This test however does not provide the same degree of information as is provided by the RFLP test.

PCR DNA testing works by "amplifying" the sample DNA, or taking a small sample of DNA and then multiplying it. This is useful if only a small sample can be obtained and is also useful for working with degraded DNA. When using PCR DNA testing however the laboratory needs to be particularly careful about preventing contamination within the sample as the amplification process could tend to increase the chances of contamination.

The process of PCR DNA testing involves heating the DNA, adding primers and then cooling it so that it recombines and an enzyme reads the DNA sequence in order to create multiple copies of the DNA.

The Restriction Fragment Length Polymorphism test takes longer than the PCR test and is a slightly older method but can provide more reliable results as each loci presents more information regarding paternity. It requires a larger sample of DNA and is more likely to use blood for the DNA testing but it can also be done using a swab from the inner cheek if necessary.

The AABB report from 2004 stated that there is a decrease in the number of laboratories using the RFLP method and an increase in laboratories using the PCR method of DNA testing with PCR being used in 98.34% of the cases.

In conclusion, there are two main methods of paternity DNA testing that are mainly used today. These two methods are Polymerase Chain Reaction testing and Restriction Fragment Length Polymorphism testing. PCR testing is used in 98.34% of the DNA testing cases according to the 2004 AABB report and seems to be increasing over the older method of RFLP. PCR is a quicker method of testing and multiplies the amount of DNA material so that only small samples are needed; however this does lead to a risk of contamination. If you are going for PCR testing or ordering a DNA home test kit you should ensure that they are AABB approved and that they offer at least a 99% guarantee and test at least ten loci.

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Judy Wellsworth asked:




In order to do a hair test for paternity, you need to have hair that still has the roots and follicles still attached. This means, taking strands from a brush will not work, you need to pull the hair from your head and look to make sure the hair follicles and roots come attached to the sample. In most cases of a paternity test, three to four strands of hair require submitting in order to do the DNA testing.

Hair test for paternity costs less than any other DNA testing and is just as reliable as any other form of testing. Genetic DNA paternity testing allows courts and individuals to confirm paternity of a child and the father or mother. These tests do hold up in court and do provide for accurate results. Most people use a clinical facility, but some receive a home test kit in the mail and send the sample out for testing.

Why do people need a hair test for paternity? In some cases, genetic DNA paternity testing is done to determine the parentage of a child. This procedure allows courts, parents and other concerned individuals to know who the parents are, whether it is for the mother or the father. This information allows the custodial parent to receive support of the said child. In most states, if you receive any kind of support from the government, you need to know the paternity of the father.

Before genetic DNA paternity testing helped to identify a father, men who were said to be a father were just that, determined and appointed the father. Today, a simple paternity test will reveal if the individual is the legal father or not. This procedure has also aided in the overturning of many rulings by the courts when confirming that someone was a father, they have been found not to be the father, which leads to hardship for many.

Earlier tests conducted used the blood type of the mother and father to determine if the baby belonged to the father. A very inconclusive test that throughout the years has caused many problems in the courts as fathers have begun to use the updated hair test for paternity as a way to prove they are not the biological father. Some people feel this could cause a big problem with child support agencies, as they try to collect from the real father after collecting support from the wrong father for years.

With the advancement of DNA testing, the entire process has helped and hindered in many areas as people use the genetic DNA paternity testing to find lost children and find missing fathers. Technology keeps advancing and so does paternity testing.

The Step-by-Step Genealogy Guide

Jason Kay asked:




You can't watch a crime drama on TV, or the news (think Anna Nicole Smith) for very long nowadays without hearing about DNA. DNA testing can tell who fathered a child. It can rescue an innocent inmate from prison, or prove the case against a criminal. DNA testing can give you an idea of certain diseases you are more likely to develop than other people. DNA can also link you with your ancestors and show you where they might have come from.

But what exactly is DNA? Deoxyribonucleic Acid is a sort of blueprint for every cell in your body. Your genes are made from DNA. You get half from your mother, and half from your father. The only two people that can have identical DNA are identical twins. In every other case, DNA is a so-called genetic fingerprint. Because it is unique, police and prosecutors look to DNA samples to help catch and convict criminals. In the legal system, DNA samples must be handled carefully.

But people can take their own DNA tests in the privacy of their homes. A blood sample is not necessary. All that is needed is a few cells from the lining of the cheek. A scraping of the lining taken with a swab is enough to do DNA testing. It is most commonly used to determine paternity.

The kit for the test can be ordered online, or bought at a drugstore. The cost for a simple paternity test runs between $100 and $250. You take your own sample, and send it to the lab. If you are trying to establish paternity, you also need a swab of the possible father's cheek, and of the child's cheek. Most labs that do this testing say that they can tell you with greater than 99% accuracy if the person sampled is the child's father, and 100% if he is not.

There are also ways to get the possible father's DNA surreptitiously. Sometimes labs can run the test from a piece of chewed gum, or a hair. Each lab is different, and less-than-perfect samples cost hundreds of dollars more to test.

What else can you do at home? You can prove other familial relationships if there is some question. You can also have your DNA tested to look into your ancestry. The National Geographic Society is even collecting DNA samples from all over the world to create a sort of genetic world map. You can participate by conducting an at-home DNA test, which costs about $100.

Some other types of home DNA testing are probably best avoided. One company says it can tell you as early as 7 to 8 weeks into a pregnancy what the sex of the unborn baby will be. This is allegedly possible because some of the baby's blood mixes in with the mother's blood. You take a sample of the mother's blood at home. If the lab finds a Y chromosome in any of the sample, the baby will be a boy, because only males have a Y chromosome. If no Y chromosome is found, the baby will be a girl. This whole area of DNA testing is not proven, and there are lawsuits at the current time against companies that reported the unborn child's sex incorrectly. There are also ethical issues even if this test were to be perfect.

Another category of DNA testing exists, genetic testing for markers of certain medical conditions. Usually, if this kind of test is necessary, your doctor will order it, and it will be done in a lab that is certified to give accurate results. More importantly, your doctor can advise you what the test means. If you have a certain gene, you have an increased probability of developing a certain disease. It doesn't mean you will get the disease, and a negative test does not mean you won't.

You can do these tests at home. But you will not have anyone to explain what the results really mean. Still, people do these tests, sometimes for privacy, or in order to prevent health insurance companies from knowing the results and perhaps raising their rates. But to test for the right conditions and actually understand what the results mean, you should see your doctor, or in some cases, a geneticist.

As of today, at-home DNA testing is best used to determine paternity or other familial relationships when there is no legal requirement, or to get information about your ancestry.

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