I ordered the Ancestry.com DNA test in July. I got my results back last week (it took about 3 weeks to get the results back). The results showed West African 44%, British Isles 29%, Scandinavia 12%, Finnish-Volga/Ural 11%, and uncertain 4%. was certain that Ancestry had mixed up my sample with another. Then 4 months after receiving my âincorrectâ DNA results from Ancestry.com, my 86 year old mother revealed that my biological father was in fact a long time family friend and not the father who raised me. My own mother confirmed the DNA test results.
In genetics, complementary DNA (cDNA) is double-stranded DNA synthesized from a messenger RNA (mRNA) template in a reaction catalysed by the enzyme reverse transcriptase. cDNA is often used to clone eukaryotic genes in prokaryotes.
After digestion of the RNA, a single stranded DNA (ssDNA) is left and because single stranded nucleic acids are hydrophobic, it tends to loop around itself. It is likely that the ssDNA forms a hairpin loop at the 3' end. From the hairpin loop, a DNA polymerase can then use it as a primer to transcribe a complementary sequence for the ss cDNA. Now, you should be left with a double stranded cDNA with identical sequence as the mRNA of interest. Applications. Complementary DNA is often used in gene cloning or as gene probes or in the creation of a cDNA library.