Try to ask a specialist about how to perform the DNA test for determining ratios, and you will find him looking under his thick glasses with indifference and simply tells you that the test makes sure that half of the child’s genetic material comes from the father.
So, without any explanation as to what genetic material means or how to determine whether it comes from the father or otherwise.
Consider these moments well as they are the last moments before embarking on a tour with a direct paternity test illustration showing you how to do this test from the ground up, taking into account as much simplification as possible.
Since scientists have discovered the role of DNA as a tool for genetic code, this discovery has begun to be used in genealogy techniques based on a simple rule:
Each child has 46 chromosomes, 23 fathers and 23 mothers; That the child gets half his DNA from his father, and the other half from his mother.
The first question, however, is how to determine half the DNA of the father and the mother.
This is the second rule: Each gene is present in a particular location of the child’s DNA. There are two copies of it, one from the father and one from the mother.
Then the descent tests began with simple analyzes such as blood group analyzes, where there are genes responsible for them and by comparing the blood of the father, mother and child, it is possible to adopt the paternity of a person or not, but this test was effective only in the denial of paternity and not proof,
Because there is a narrow group of blood groups in humans, and the probability of similarity between the blood type of a person and a child does not necessarily mean that his father, while the lack of similarity between the right person and the child confirms the lack of paternity.
Gene DNA testing As DNA discoveries progress, scientists are able to detect sites in DNA on different chromosomes. These sites are in the form of a repetitive sequence of DNA constructs, varying from person to person in length – frequency.
The advantage of this discovery is its ability to identify by: Scientists have discovered about 13 sites for these repetitive sequences.
There is a wide range of repetition rates that varies from person to person.
Each person has two copies of these repeating sequences.
A copy of these repetitive sequences of the father and a copy of the mother are transmitted to each person.
Mathematical equations for the probability of two people sharing the same complete sequences indicate that this is almost statistically impossible.
Thus, the basic steps for testing modern genealogy through DNA are:
A sample of the child’s cells and the father’s cells are collected to extract their respective DNA.
During the sample examination, 13 sites are considered for globally agreed DNA. The 13 DNA sites have copies of each of them in the child (a copy of the father, and a copy of the mother).
These sites are identified by their length (each site has a specific range of lengths, and the exact length varies from person to person).
As long as one copy of each of the child’s 13 sites is identical to one of the two versions of the same site in the DNA of the father, this indicates that this person is the father by evidence that the DNA contains half the genetic material of the child.
To illustrate the DNA analysis for son ratios, we will give a real example of an analysis to ascertain the proportions of a child to his father.
A simple, straightforward example of DNA testing for the child and comparing it with the DNA of the mother and the presumed father:
First, a DNA sample is taken from the child, father and mother.
Second, the 13 sites are examined on the DNA to determine the length of each.
Thirdly, it is noted that each of the 13 sites has two versions of each different length, such as the following table.
Fourth: Make sure that one of the two copies on each site taken from the father as follows:
Thus it can be shown that this person is the real father of this child by 99.9%
If a copy of a DNA site exists in the child and does not exist in the other person, it is unlikely to be 100% true.
DNA tests for the detection of ancestors
The above is the method of paternity tests, but do not forget that there are many advanced techniques for studying DNA that help to determine the relations between all members of the family and between peoples and nations and the extent of their participation in the assets associated with them according to DNA.
Read also: How do I know I am pregnant with twins?
Precautions Procedure for DNA Determination Determination:
So our tour with DNA tests and determination of ratios is over, and we hope that we have adapted to simplify the idea of real analysis away from the abbreviated detail and complex details.