"purifi" - 1 õppematerjal

Liha töötlemine

reagents can reduce or even block the PCR quality must be evaluated by means of UV amplification, and DNA may be degraded. spectrophotometry at 260 nm; by fluorimetry Food components that can act as PCR inhibi- using fluorescent ds-DNA-specific dyes; or tors are proteins, fatty acids, and other sec- by visualization under UV light of DNA ondary compounds such as polyphenols. separated in agarose gels stained with ethid- Consequently, adequate nucleic acid purifi- ium bromide. Before DNA estimation, RNA cation is crucial to convert food samples into must be carefully eliminated in order to avoid samples amenable for amplification by adap- an overestimation of yield. For this purpose tation of extraction procedures to each food a straightforward treatment with RNAase A matrix. The first stage is homogenization to is recommended. Then, it is simple to cor-