an efficient dna extraction method for lactobacillus casei, a difficulttolyse bacterium

Background: there are several protocols to extract dna from lactobacillus spp. in the case of l. casei it is harder because of its especial and thick cell wall. objectives: in this study, nine dna extraction protocols (by lysozyme treatment) were evaluated and compared in two categories (traditional and kitbased protocols) and an improved method was presented. materials and methods: dna quantity and quality was determined by spectrophotometry, agarose gel electrophoresis and polymerase chain reaction (pcr). results: the results revealed that the yield of extracted dna differed by each protocol (5.8 17.1 μg/100 μl), but provided appropriate dna for pcr amplification. the modified protocol offered the best total dna extraction method when both quality (dna purity; 1.54 μg) and quantity (dna yield; 17.1 μg) were considered. conclusions: we suggest this protocol for effective and inexpensive dna isolation from l. casei for downstream biological processes such as pcr.