Application Examples - nanoXtract Kit

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Purify & Concentrate DNA from Fresh or Frozen Blood: over a range from 200µL to 0.05µL.

PrepParticles have been coupled to standard protease digestion, allowing the release, isolation, capture and recovery of purified DNA from blood samples as large as 200µL or as small as 0.05µL: all steps performed in a single, standard microfuge tube. The purified DNA product is then released in a PCR-compatible buffer, in volumes as small as 10µL. Work is in progress to scale-up this isolation protocol to accommodate the purification of DNA from blood samples as large as 2ml (about 60µg of DNA) also as a one-pot reaction in a standard 15ml conical centrifuge tube.

Purify and Concentrate DNA from Cloth Samples or Forensic Wipes.

In crime scene forensics, DNA is often obtained for analysis by surfaceSample from Dried Denim wiping with a cotton swab or directly from cloth such as denim. This application is particularly demanding, in that the surface-bound DNA may be very dilute, yielding less than 10 nanograms of DNA per sample. A PrepParticle application has been developed for such surface wipes, based on processing of air-dried swabs. This method has been validated with 1 microliter-size blood spots that were air dried and stored at room temperature, on glass slides for 10 months. High quality DNA was obtained from these microliter-size dried blood spots after having been transferred to a sterile cotton swab. The yield of DNA obtained from such wipes using the PrepParticle process approached the limit that would be predicted from ordinary blood with a normal white cell count (20-30 nanograms of DNA per microliter of blood). The quality of DNA from these samples was assessed by length-dependant PCR and by the ABI Identifiler assay. Both indicated that the DNA from these blood spots performed as well as highly purified DNA controls in the same assays, demonstrating that the DNA product was free of detectable PCR contaminants. top

Purify and Concentrate DNA from Dried Blood Stored on FTA Paper or Guthrie Cards.

FTA or Guthrie Cards Dry state storage of whole blood or other DNA sources is becoming a key technology for forensic database building, biosecurity applications, and for population scale genetics. We have obtained yields of up to 250 nanograms of high quality DNA per 10µl of dried blood on FTA, which is near to the expected limit based on white count. The DNA can be eluted in a final volume as small as 10µl and is found to be free from measureable PCR inhibitors. top

Purify and Concentrate DNA from Buccal Swabs.

DNA collection via a cheek wipe has become the standard in large-scale Buccal swabs forensic database development and, more recently, for population-scale genetic epidemiology. The literature suggests that DNA yields from such cheek (buccal) wipes are in the 0.2 to 1 microgram range. Argylla has developed a PrepParticle protocol for the quick and easy purification and concentration of DNA obtained from such cheek wipes. Briefly, cells are collected by wiping the inner cheek with a sterile cotton swab followed by air-drying. The swab is then re-hydrated and subjected to protease digestion by the FBI-standard process for 4 hours at 56C, followed by centrifugation of the swab to isolate the fluid sample in about ½ ml. The raw, protease digested DNA sample is then diluted to 500 microliters, followed by a standard PrepParticle isolation. The resulting DNA preparation can then be analyzed by the standard human Identifiler STR panel or any other PCR based test. Quantitation via PicoGreen fluorescence demonstrates DNA yields in the 500ng to 2µg range. Because the sample is purified, concentrated and released for analysis as a one-pot reaction, sample tracking and chain of custody are greatly enhanced. top