Genomic DNA Extraction Kit

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Q&A

Why does the genomic DNA band appear smeared in agarose gel electrophoresis?

Plasmid DNA Extraction Kit(PD004, PD100, PD300) --Q&A
　

Q	Why do we sometimes obtain a lower yield?
Q	Why doesn’t the Eluted DNA perform well in downstream applications?
Q	Can the plasmid DNA extraction Kit be applied on Gram (+) bacteria?
Q	Why do we get eluted plasmid contaminated with RNA?
Q	Why can’t the eluted plasmid be cut by restriction enzymes properly?
Q	Why does the Plasmid DNA Extraction Kit require two washings with two types of wash buffers (W1 and Wash Buffer) while competitors kits require one washing?
Q	Eluted plasmid appeared degraded after storage for an extended period of time.
Q	Why was Restriction enzyme digestion unsuccessful?

Genomic DNA Extraction Kit(GT004,GT050,GT300,GB004,GB100,GB300,GP004,GP100)--Q&A
　

Q	What should be done if the Column is clogged?
Q	Why is the DNA recovery lower than expected?
Q	Why doesn’t the Eluted DNA perform well in downstream applications?
Q	Why does the genomic DNA band appear smeared in agarose gel electrophoresis?
A	Several points should be noted to avoid DNA degradation: (1) DNA degradation occurs when the sample is not fresh or is stored improperly for a long time. Samples not used immediately should be flash frozen in liquid nitrogen and stored at -80°C. Genomic DNA in samples stored at room temperature, 4°C, or -20°C are subject to degradation. It is also not advised to keep samples in buffer or medium while storing at -80°C. (2) For whole blood samples, if they are stored at room temperature for more than 2 days or at 4°C or -20°C, isolated genomic DNA appears smeared at an extent proportional to the storage time. (3) Use fresh TAE or TBE running buffer for electrophoresis. Running buffer that is used repeatedly may be contaminated with DNase. (4) If isolated DNA needs to be stored for a long time, use 10 mM Tris-HCl (pH 9.0) or TE for elution. Using ddH2O is not advised in this case as DNA fragments in H₂O suffer from gradual degradation through acid hydrolysis. (5) If DNA is to be used frequently, elute in 10 mM Tris-HCl (pH 9.0) or TE and store at 4°C. Keep DNA at -20°C only for long-term storage. Repeated freeze-thaw cycles can cause shearing of genomic DNA. (6) Genomic DNA extracted from paraffin-embedded tissue is usually degraded. This is because genomic DNA in paraffin-embedded tissue unavoidably suffers from degradation when samples are treated and stored for a long time. DNA in this case is not suitable for Southern blotting or restriction analysis due to smearing. However, it is applicable for PCR.
Q	What is the key to successfully isolating genomic DNA of good yield and quality?
Q	Why does the sample appear viscous after sample Lysis and not pass through the column easily, even when less than the suggested maximum sample amount is used?
Q	When Buffy coat is used, the column tends to be clogged.

Gel/PCR DNA Fragments Extraction Kit (DF004, DF100, DF300)--Q&A

Q	Can the Gel/PCR DNA Kit completely remove primers or dimer products from PCR reactions?
Q	Can the Gel/PCR DNA Fragments Extraction Kit be used to clean up DIG-labeled DNA fragment?
Q	A band, smaller than the desired DNA fragment is present in the eluant.
Q	Why DNA recovery is lower than expected?
Q	Why doesn’t the Eluted DNA perform well in downstream applications?

RNA Related Products(RT050,RT100,RT300,RB050,RB100,RB300,RP050,RP100)--Q&A

Q	How do I increase yields of total RNA?
Q	Why does the obtained RNA appear smeared and degraded?
Q	Is total RNA isolated by the Total RNA Extraction System free of genomic DNA?
Q	What is the most suitable kit for Cytoplasmic RNA extraction?
Q	What is the function of the lysate filter columns?
Q	Which kit is suitable for RNA extraction from yeast?