DNA extraction is a necessary method in many molecular biology applications. There are many commercial kits that can help with this process. However, through PCR detection, the extraction efficiency of different types of kits is different. We can use machines to assist our experiments-DNA extractor and RNA extractor to ensure better results.
Choosing the right kit can save more valuable time for the optimization and implementation of the experiment. The factors that should be considered when choosing a kit are:
1. Sample source: Different kits are used for different sample sources, including human tissues, blood, hair, rodent tissues, plant leaves, bacteria, yeasts, fungi, insects, feces, body fluids, spores, soil, clinical Samples (such as biopsy samples and puncture samples), forensic samples (such as dried blood and buccal swabs), and fingerprints.
2. Preparation method: Sample preparation can be: fresh or previously prepared frozen cells, paraffin-embedded or formalin-fixed tissue sections, frozen tissue sections, ethanol-fixed cells and Oragene®-preserved samples.
3. Purpose of use: The quality and purity of the DNA extracted by the kit should be suitable for subsequent experimental purposes, such as sequencing, fingerprint verification, PCR, qPCR, Southern blotting, RAPD, AFLP and RFLP detection, restriction enzymes Digestion, genome sequencing.
4. Humic acid content: If the sample contains humic acid, such as mixtures, sediments and manure, it is necessary to use a certain kit or method to remove humic acid, because such substances will affect the subsequent DNA detection. Such as PCR.
5. Sample content: The choice to use a certain kit depends on the number of cultured mammalian cells (105-107) and bacteria (106-1011), tissue mass (mg), blood volume (100 ul to 1 ml), and soil Mass (250 mg-10 g), plant leaf mass (mg), etc.
8. Simplicity: the use of the kit depends on the experience of the operator
The basic conditions for purifying DNA from any type of sample include:
(1) Efficient extraction,
(2) Extract enough DNA for subsequent experimental procedures,
(3) Remove residual pollutants,
(4) The quality and purity of DNA. UV absorbance can be used to evaluate the purity of the extracted DNA. For pure DNA samples, the ratio of UV absorbance between 280 nm and 260 nm (A260/A280) is 1.8. A ratio of less than 1.8 indicates that the sample is contaminated by organic solvents such as protein or phenol.
Commonly used DNA extraction and purification kits:
lCommercial kits: DNA extraction from microorganisms; DNA extraction from animal cells and tissues; DNA extraction from plant tissues and cells; kits for animal tissues and cells; DNA extraction reagents for mammals, microorganisms and plant cells box.