RESUMO
Here we report a rapid and cost-effective method for the extraction of total DNA from herbarium specimens up to 50-90-year-old. The method takes about 2 h, uses AMPure XP magnetic beads diluted by PEG-8000- containing buffer, and does not require use of traditional volatile components like chloroform, phenol, and liquid nitrogen. It yields up to 4 µg of total nucleic acid with high purity from about 30 mg of dry material. The quality of the extracted DNA was tested by PCR amplification of 5S rRNA and rbcL genes (nuclear and chloroplast DNA markers) and compared against the traditional chloroform/isoamyl alcohol method. Our results demonstrate that the use of the magnetic beads is crucial for extraction of DNA suitable for subsequent PCR from herbarium samples due to the decreasing inhibitor concentrations, reducing short fragments of degraded DNA, and increasing median DNA fragment sizes.
Assuntos
Asteraceae/química , Asteraceae/genética , Botânica/métodos , DNA de Plantas/isolamento & purificação , Técnicas Genéticas , Clorofórmio/química , DNA de Plantas/análise , DNA de Plantas/metabolismo , Fluorometria , Técnicas Genéticas/economia , Pentanóis/química , Folhas de Planta/química , Folhas de Planta/genética , Polietilenoglicóis/química , Reação em Cadeia da Polimerase , RNA Ribossômico 5S/genética , Ribulose-Bifosfato Carboxilase/genética , EspectrofotometriaRESUMO
The effect of microwaves on liquid water was investigated by using biosensors and physiochemical techniques, such as nuclear magnetic resonance (NMR) and spectrophotometry. The results obtained provided evidence for a nonthermal effect of microwaves on liquid water.