DNA-testing the Norwegian government sometimes ask immigrants in Norway to do a DNA-test in relation to applications of family reunifications and requests for asylum to find out if people really are related. What should a Muslim do if they ask you to make a test to see for instance to check if you are the father to your children.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

We do not see any harm for a Muslim to accept this kind of testing if the government asks him to do so. However, it should be noted that in order to prove the family lineage, there are some Islamic conditions that are taken into account in Islamic legislation and not this kind of testing. The Prophet said: "The boy is for the owner of the bed and the stone is for the person who commits an illegal sexual intercourse (i.e. the child will not be traced back to him)." [Al-Bukhari and Muslim]

So whoever has a wife and she gives birth to a child on his bed, it is his child and is traced back to him. It is only by Li’aan (which is when both spouses make an oath that he/she is truthful in his/her claim and then invoke the curse of Allaah on the one who is lying. This takes place when the husband accuses his wife with adultery, and is done in front of the ruler or the judge) a child could be denied by the husband that he is not his.  [The method of cursing is mentioned in Fatwa 89532]

Allaah Knows best.