It should be said that extracting DNA and RNA from whole blood is * basic work. The quality of extracted DNA and RNA directly affects the downstream experiment and analysis. There are many methods to choose. Flowers are becoming more and more attractive. How to choose * suitable methods has become a difficult choice for many people before the experiment. We peel cocoons layer by layer from two aspects and analyze * good experimental methods.

1. Collection and preservation of whole blood and extraction of DNA

1. Blood collection is carried out with blood collection vessels containing anticoagulants. Anticoagulants generally include EDTA and heparin. EDTA is better and will not affect the downstream reaction. If there is no blood collection vessel, you can also add anticoagulant EDTA yourself, prepare 0.04m EDTA solution in advance, add 0.4ml prepared EDTA solution every 5ml of blood, and mix it upside down. Stored at - 20 ℃ to - 80 ℃, it can generally be extracted within 2-3 years. The shorter the storage time, the higher the extraction quality, * it is better to extract within 2 months.

2. Selection of DNA extraction methods: whole blood extraction kits generally include centrifugal column and solution type (such as Qiagen, Promega and bioteke; The method of abandoning phenol chloroform is long-time and toxic), and the principle and steps are basically the same. Although various companies have launched more than n models, people do not know how to choose, but from the perspective of principle and operation steps, they are basically centrifugal column and solution type. Generally speaking, the extraction purity of centrifugal column (dp1801) is higher, but the treatment capacity is small (0.1-1ml) and the yield is slightly low; The extraction amount of solution type (dp2101 or dp2201) is large (1-10ml), and the yield is also higher than that of centrifugal column. When it comes to the difference between domestic and imported, many people think that imported blood must be better than domestic blood. We think it's not * good, but better! After continuous experimental optimization, the whole blood genomic DNA Extraction Kit dp2101 or dp2201 has created the third generation technology, which does not need protease K digestion, and all imports need the help of protease K! Dp2101 or dp2201 reduces the trouble of preparing and using protease K and the digestion time, and the extraction amount and stability are better.

2. How to extract RNA from whole blood

1. What are the factors of RNA degradation in the whole blood RNA extraction process?

RNase is very abundant in whole blood. RNA is easy to degrade without protection! What is the state RNA that is not protected? For example, in the process of red blood cell lysis with red blood cell lysate, the red blood cell lysate is a low concentration equilibrium salt solution, which does not stop the composition of RNase. At this time, RNA is not protected; RNA is not protected during DNA enzyme digestion, and RNase is not stopped at this time.

2. What kind of extraction method is better?

When choosing methods, we should tend to protect the whole process of RNA! The general method is to first lyse red blood cells with red blood cell lysate, then extract nucleic acid from white blood cells, and then digest and remove DNA by DNase. This is not a good method. There are many factors of RNA degradation in the process. Therefore, the direct lysis method is a good method. Quickly add the collected blood into the lysate rls-rp4001 total RNA rapid extraction kit (centrifugal column type) of three times the volume of lysate, and quickly reverse and mix it. Lysate RLS contains strong protein denaturant, which can denature protein rapidly. It is RNase denaturation and cannot degrade RNA. The lysed mixture can also be used for transportation to avoid RNA degradation. This method has become the recommended method for RNA transportation and extraction of Boao biological expression profile chip