Purification of DNA
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There are several methods for purifying DNA. The one you choose depends on the nature of your DNA sample and your downstream applications.
- Ethanol precipitation of nucleic acids
- Ethanol precipitation of small DNA fragments
- Isopropanol Precipitation for PCR Purification
- use to concentrate DNA from PCR when you have verified that only a single PCR product exists. When performed properly this procedure exceeds the recovery of QIAquick PCR purification columns
2-propanol (isopropanol) precipitation yields less DNA than EtOH precipitation. (In my hands 60% less on average! Jasu) 2-propanol at RT reduces the risk of co-precipitation of salts (which can interfere with downstream experiments). 2-propanol is preferred for large volumes of DNA since less alcohol is required, plus it's faster since it doesn't require a cooling step. Glassy pellets from 2-propanol precipitation are harder to see than fluffy, salt-containing pellets from ethanol precipitation. 2-propanol pellets are also more loosely attached after centrifugation. Take care when decanting.