Comparison of different methods for extraction of DNA of fungal pathogens from cultures and blood.

Five commercially available extraction kits and an in-house DNA extraction method for the release of DNA from Candida albicans and Aspergillus niger cells were assessed for sensitivity, purity, duration, and cost. All commercially available kits helped to shorten the duration of DNA extraction. However, the sensitivity varied from 1 to 1,000 fungal cells/ml and costs varied from $0.10 to 2.30. The QIAmp Tissue kit was the commercially available assay that yielded the same sensitivity and purity of fungal DNA release as the in-house protocol but was the most expensive method. In comparing these two extraction protocols, a 99% concordance of PCR results for 125 blood samples analyzed could be demonstrated.