Polymerase chain reaction (PCR) has been widely used due to its high specificity, sensitivity, and rapid turn-around time. However, the major limitation of PCR based diagnosis is inhibition of the reaction caused by a variety of components within clinical specimens. The demand for PCR diagnosis in medical microbiology has highlighted the need for efficient methods of nucleic acid extraction. Although there has been progress in the simplification and purification of microbial nucleic acids, many researchers' procedures are still inconvenient for routine use with any specimen and a universal method has not been devised yet. In this review, some of the basic principles for extraction procedures that have been used to date and the present situation of nucleic acid extraction are summarized.

Polymerase chain reaction (PCR) has been widely used due to its high specificity, sensitivity, and rapid turn-around time. However, the major limitation of PCR based diagnosis is inhibition of the reaction caused by a variety of components within clinical specimens. The demand for PCR diagnosis in medical microbiology has highlighted the need for efficient methods of nucleic acid extraction. Although there has been progress in the simplification and purification of microbial nucleic acids, many researchers' procedures are still inconvenient for routine use with any specimen and a universal method has not been devised yet. In this review, some of the basic principles for extraction procedures that have been used to date and the present situation of nucleic acid extraction are summarized.