if dna can be ascertained from a blood drop what happens when someone has had a transfusion?

Question

does your body adjust the dna in the new blood

Answer 1

Blood cells do not carry DNA, since they don't have nuclei.

Answer 2

This is actually a really cool question. First of all, your body does not "adjust" the DNA in the new blood. There is no mechanism whereby your body might do this, since blood transfusion is not a normal biological process and your body has not evolved to deal with this situation. Second, there are many different kinds of blood transfusions which contain various subfractions of the blood. Most blood components do not contain DNA - red blood cells do not contain nuclei (which hold the DNA), and plasma does not contain cells. However, white blood cells (leukocytes) DO contain nuclei and DNA, and except in the case of leukoreduced transfusions, will be transfused into the blood. So, it's possible that DNA from transfused blood could show up as a positive in a DNA test.

However, it's relatively unlikely: first, it would require that the sample you are testing against is blood. Most DNA tests are done via cheek scraping samples, not blood samples. So only in situations where some blood is spilled at a crime scene would this be an issue. Second, you would be extremely unlikely to come across a situation where you and your blood donor would be suspected, since most transfusions come from anonymous donors. Third, the white blood cells from a donor would have a short lifetime in your blood stream (your immune system would destroy them), so they probably wouldn't be around long enough to turn up in a blood sample, unless it was just a few days after you had received a transfusion. But all of these could, in strange circumstances, happen.

Answer 3

Transfused blood does carry donor dna, eg the white blood cells. It could therefore be detected in a sample of the recipients blood at low levels. However after the lifetime of red and white cells in the body ( about 8 weeks) the foreign dna would be degraded and not replicated.

Answer 4

The DNA is still foreign- you just have someone elses blood pumped through your body. There are no nuclei in the red blood cells but there are in other cells carried in the blood. Eventually, once all the blood cells have died, there will no longer be any foreign DNA in the body, but the DNA in the trafused blood stays the same as the giver and different to your own (unless it was transfued from an identical twin).

Answer 5

Red blood cells do not have DNA. The surface of red blood cells have two flag poles. This first carries the A or B flag, both A and B or neither = O The second either has the Rhesus flag or it does not. Your body will attack any cell with a foreign flag (a flag it does not have) If you are O (no A or B flags) Negative (no Rhesus flag) you will attack any cells who are not the same. If you are AB Positive, you will be OK with any blood given. O negative is known as universal donor as there are no flags to object to. AB Positive is the universal recipient as any blood given will be accepted. It is all about the blood given being compatible withe receivers blood. Although the blood being given can contain antibodies to the recipient it will not do any major harm as it is just a pint or two of blood and does not have the resources of a whole body to mount an attack on the receivers blood. To complicate matters there is a blood type called the Bombay Blood group, which does not even have the flagpoles. These make good donors but people with this blood type will attack even O negative donations.

Answer 6

Red blood cells don't contain DNA, but white blood cells do. Usually only red blood cells are used for transfusion. In cases where all the blood has been transfused no trace of any foreign DNA has ever been found.

Answer 7

Red blood cells have no DNA, or nucleus. The DNA is taken from the white blood cells that have a nucleus.

The blood in transfusions has been purified and your own white blodd cells would destroy any foreign white cells.

Answer 8

You have someone else's DNA floating around in you for a little while. Eventually it will dissappear, being replaced by new blood, until it is all gone.

If you have a DNA test then some of the blood will show the wrong DNA, but most of it will show the right DNA.

Answer 9

There is a continuous destruction of cells and of course of DNA,that DNA will not last too much, its components are recycled.

Answer 10

They separate the plasma and the solution when taking blood and then just add saline solution so it has no DNA, only its own DNA not the persons.