Figure 1. A funnel-shaped ring holds a silica membrane with a very small diameter. The exceptionally small (2.0 mm) diameter of the NucleoSpin Tissue XS membrane allows efficient elution in just 5–30 μl, resulting in high DNA concentrations and a purification product that is ready for all typical downstream applications. High DNA yields and small elution volumes result in highly concentrated DNA, free of impurities and suitable for sensitive downstream applications.

Figure 2. Elution volume depends on membrane diameter. The extra-small diameter of the NucleoSpin Tissue XS membrane compared to that of competitors allows for efficient elution in just 5–30 μl, yielding a more concentrated eluate. The kit provided by Competitor Q (designed for very small samples) lacks these optimized column features, requiring elution in higher volumes (20–100 μl).

Figure 3. Higher DNA concentrations and total yield can be obtained with NucleoSpin Tissue XS than the leading competitor kit. Genomic DNA was purified from small amounts of murine liver tissue using NucleoSpin Tissue XS and a competitor's kit specially designed for very small sample amounts. With both kits, DNA was eluted in 20 μl of elution buffer. The DNA was subsequently subjected to LightCycler analysis. NucleoSpin Tissue XS was superior in both DNA concentration (Panel A) and total yield (Panel B). With NucleoSpin Tissue XS, the DNA concentration can be further increased by using smaller elution volumes down to 5 μl. The smallest default elution volume for the competitor kit is 20 μl.

Figure 4. DNA purification from microdissected, formalin-fixed, paraffin-embedded (FFPE) tissue. DNA was purified from microdissected FFPE colon cancer tissue with NucleoSpin Tissue XS. Sample sizes were 1 mm², 0.5 mm², 0.25 mm², 0.125 mm², and 0.065 mm² of a 4-μm slice. The isolated DNA was used directly for PCR with primers specific to PAH and K-ras. NucleoSpin Tissue XS allowed purification of amplifiable DNA even from very small samples of this FFPE tissue. Data kindly provided by S. Staeck, Dr. D. Kuester, Dr. A. Poehlmann and Prof. R. Schneider-Stock, Department of Pathologie, Molecular Genetics, University of Magdeburg, Germany.