paternity tests were
conducted using the blood types of
each parent and that of
the child, but were in no way conclusive. If the father was Type A
and the mother Type B, the only way the child might not be his, was
if it was Type O. That left a huge margin for error or
paternity testing on the other
hand, is almost
100% conclusive in its results. It cannot tell the difference between
two brothers’ particular DNA, but it can definitely show from
family the DNA originated. As long as the two possible parents in
question are from different families, DNA paternity testing will work
example, someone might claim to be a descendent of Thomas Jefferson.
Conclusive testing back to his family can be done, but since Thomas
Jefferson had at least one brother, the DNA would conclusively prove
from Thomas Jefferson’s
family did indeed pass
their DNA down through a different bloodline than that of the
accepted family tree. Jefferson yes; Thomas, who knows?
paternity testing works by isolating the DNA of both parents, and
then comparing it with the child’s DNA. The comparison is
to that of blood testing, but individual DNA is being examined, as
opposed to broad blood types.
isolate the DNA, a sample of saliva is swabbed from the mouth, and
the DNA extracted using a restriction enzyme that cuts the DNA into
identical and easily manageable lengths. The cut DNA pieces are then
sorted according to size by the use of a special gel. The DNA is
placed at one end of a slab of gelatin and is then drawn through the
gel by an electric current. The gel acts like a sieve, allowing
small DNA fragments to move more rapidly than larger ones.
result is that after the gel has separated the DNA according to size,
a blot is made to trap the DNA in their positions, with small DNA
fragments near one end of the blot and large ones near the other end.
The blot is now treated with another piece of DNA called a probe
that binds to the DNA on the blot. If the patterns are identical, the
result is a conclusive match. The technician can then reveal his
findings of his DNA paternity testing to the courts or law
enforcement agencies that may require the evidence to prosecute a
deadbeat dad, or allow a misnamed man to go free.