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View additional product information for DNAzol™ BD Reagent, for isolation of genomic DNA from whole blood - FAQs (10974020)
9 product FAQs found
颜色是因为加入DNAzol试剂前发生了细胞裂解。红色是由血红蛋白产生的。这种污染会导致PCR出现问题，因此，必须在乙醇洗涤步骤前去除颜色。以下是导致污染的可能原因：
•不充分或无效的抗凝血剂可导致血块形成；通常，这会使DNA出现斑点状外观。可在沉淀DNA前通过离心去除血块。
•未使用DNAzol BD洗涤液充分清洗试管壁。若试管壁的痕量蛋白质在乙醇洗涤过程中脱离试管，则会导致污染。
使用DNAzol试剂分离得到的实际上是总DNA，所以质粒DNA也会和基因组DNA一并分离出来。线粒体基因组与质粒类似，也可通过DNAzol试剂分离出来。可将离心步骤之前的乙醇室温孵育步骤从1分钟延长至5-10分钟，以获得最大的DNA得率。
我们推荐将DNAzol试剂储存于室温。DNAzol的裂解物（匀浆）可于15–30°C下储存1个月；在4°C或–20°C条件下储存10个月之后，DNAzol裂解物（匀浆）中仍能够提取得到高分子量的、可被限制性内切酶完全酶切的基因组DNA，且DNA在PCR反应中也可以得到较好的结果。在漂洗阶段，DNA可以保存于95%的乙醇中，在15°C至30°C至少储存一周，或4°C左右条件下至少储存三个月。DNA保存于DNAzol试剂中，可于室温下储存一个月，或4°C下储存十个月。
请浏览此网页（https://www.thermofisher.com/us/en/home/life-science/dna-rna-purification-analysis/dna-extraction/genomic-dna-extraction/blood-dna-extraction.html），该网页介绍了从血液中分离基因组DNA的各种试剂盒的特点。
The color is due to cells lysing before the DNAzol Reagent is added. The color is caused by hemoglobin. This contaminant will cause problems during PCR, and must be removed before the ethanol wash step to prevent them. The following are possible reasons for the contamination:
- Inadequate or ineffective anticoagulants can result in clot formation; typically, this will give DNA a speckled appearance. Remove them by centrifugation before precipitating the DNA.
- The walls of the tube were not adequately washed with the DNAzol BD wash solution. Trace amounts of protein on the wall of the tube can cause contamination if this residue is dislodged during the ethanol wash steps.
The DNA isolated is actually total DNA, so plasmid DNA will be isolated along with genomic DNA. The mitochondrial genome is similar to a plasmid and can be isolated using DNAzol Reagent. The 1 minute room temperature incubation in ethanol before centrifugation should be extended to 5-10 minutes for maximum recovery.
We recommend storing DNAzol Reagent at room temperature. The DNAzol lysate (homogenate) can be stored 1 month at 15-30 degrees C; after 10 months at 4 degrees C or -20 degrees C, the DNAzol lysate (homogenate) has yielded high molecular weight genomic DNA, which can be completely digested with restriction enzymes and works well in PCR. During washes, DNA can be stored in 95% EtOH for at least one week at 15 degrees C to 30 degrees C or for three months at approximately 4 degrees C. DNA can be stored in DNAzol Reagent for one month at room temperature or 10 months at 4 degrees C.
Please see the following web page (http://www.thermofisher.com/us/en/home/life-science/dna-rna-purification-analysis/dna-extraction/genomic-dna-extraction/blood-dna-extraction.html) for a comparison of kits that can be used to isolate genomic DNA from blood.
Consider the following if you have a low 260/280 ratio:
The correct amount of DNAzol reagent may not have been used. If DNAzol reagent was added to a cell pellet, make sure that the volume of reagent is 20 times that of the cell pellet.
There may have been a problem in pipetting away the viscous supernatant from the DNA pellet, leading to contamination with protein. The DNA may be used with DNAzol reagent again or extracted with phenol to remove the protein.
In some samples dissolved in water, the ratio may be low due to the acidity of the water or the low ion content in the water. The ratios may go up if the sample is dissolved in TE and the spec is zeroed with TE (or 1 to 3 mM Na2PO4, pH ~8.0). [See BioTechniques 22:474-6, 478-81 (1997).]. The molar extinction coefficient of the nucleotides is given at neutral pH, suggesting that the absorbance at 260 nm would be highest at neutral pH. Of course, DNA is not stable under acidic conditions so degradation may occur if the DNA is left in this condition for too long.