The author compared nine methods for isolation of specific DNA of the etiological agent of human granulocytic ehrlichiosis from human blood for examination of the PCR. To full blood of healthy donors a laboratory culture of the agent was added and the effectiveness of isolation an stability of the template was tested under conditions when the blood was fresh or frozen. For universal use QIAamp® (QIAGEN) was most suitable, frozen blood was extracted best using NucleoSpin® Tissue (Macherey-Nagel).

        Key words: human granulocytic ehrlichiosis (HGE) – Anaplasma phagocytophila – polymerase chain reaction (PCR) – DNA extraction.