A magnetic bead-based system for DNA isolation utilizing monodisperse beads was tested with the aim of producing a general approach for PCR-ready DNA. This commercially available system was originally designed for isolating PCR-ready DNA from human whole blood. We tested diverse organisms belonging to the major groups: bacteria, fungi, algae, vascular plants and vertebrates. Optimization of sample amounts and lysis conditions was done using several types of tissue (fish epithelium, plant leaves, mammalian liver and muscle tissues, fungal fruit-bodies and mycelium). The standard lysis conditions used for blood could be applied with good results for most bacteria, algae and vertebrates, while plant leaves and fungal fruit-bodies had to be mechanically broken to obtain proper lysis. For vascular plants and some cyanobacteria, lysis by heating to 65°C gave better DNA yields than standard lysis at room temperature. In all cases, DNA suitable for PCR was prepared in less than 30 min. The PCR products yielded 35...