A molecular biology laboratory come from clinical different types of samples, each with its own peculiarities to the analysis and obtain his DNA. "A priori" two different situations arise. If the aim is to know the physical location of the DNA / RNA of interest in a histological section shall be undertake studies in situ, whereas if it is not necessary to know that location is sufficient to obtain cellular DNA in solution. The DNA in solution is a mixture of mitochondrial DNA, eukaryotic nuclear and viral / bacterial if present in the sample virus / bacteria. (more...)