I come across something called a tris solution in the protocol for isolation of bacterial dna.. i have tried everywhere but yet to find what it is actually.. can anyone help

Why does a careful alkaline treatment followed by neutralization preserve plasmid DNA, but leave chromosomal DNA as mostly single stranded fragments? (dealing with a purification and identification of Recombinant DNA protocol)

I’ve been put in charge of genotyping some blood and I don’t have a protocol. My main question is, after DNA isolation and checking the concentration of DNA, do I then add the PCR mix and then the Master Mix? Are the PCR mix and the Master Mix the same thing? I know after that, I just go ahead, run the PCR, then run the gel, but I’m confused on those two steps. THANKS!

Want to make Phenol:Chlorofrom:Isoamyl alcohal (25:24:1) solution for DNA extraction. But the phenol is in crystal (solid) form. How to dissolve and how much. Protocol is well come.

I am trying to extract DNA using Qiagen’s DNeasy extraction kit, and having a problem with my samples.
My samples are nucleated blood collected few months ago. They are apparently coagulated and very gelatinous. It is impossible to pipet 5 to 10 ul of the sample, so I used tweezers and cut out pieces of about the size of 10 ul drop of water.
However, after adding proteinase K and buffer AT, they cannot be homogenized as the protocol requires. I have incubated them at 56 C, and some did dissolve, but black residues remain in the tubes after 30 min.
Is there a way to make the blood more fluid? Will the DNA be damaged if I incubated at 56 C overnight with Proteinase K?
Any advice or comment is appreciated.

Refering to Cheng, H.R., and Jiang, N., (2006) "Extremely rapid extraction of DNA from bacteria and yeast", Biotechnology Letters, 28: 55-59.
I followed most of the protocol, except that I used P:C:I (25:24:1) instead of tris-saturated phenol.
1. 1ml of culture, centrifuged, washed with STE buffer twice.
2. Resuspend cell pellets with TE buffer
3. Add 1x volume of P:C:I (25:24:1), vortex for 60secs.
4. Centrifuge at max speed for 5mins at 4C.
5. Transfer aqueous layer to new tube, mix with 1x volume of chloroform, centrifuge at max speed for 5mins at 4C (repeat until no white interface is present)
6. Transfer aqueous layer to new tube, add RNase A, incubate at 37C for 30mins
7. Add 1x volume of chloroform, mix and centrifuge at max speed for 5mins.
8. Transfer aqueous layer (which theoretically should contain pure DNA) to new tube and store at -20C
Before RNAse A treatment, I can see a >10kb band n trace of RNA, however after the treatment, no band was seen. Why?

protocol followed with Kiwi

http://biotech.biology.arizona.edu/labs/DNA_Kiwifruit_teacher.html

Hey everybody. I’m a final year student and I have to do some experiments with SSR (simple sequence repeat) indicator. Now I’m preparing to cloning some genes and I have some troubles. It’s the DNA extraction stage, but from 6% silver- staining polyacrylamide gel (normally, in my lab, they just extract from agarose gel). I need some advices about the protocol and the difference between the ethidium bromide – staining polyacrylamide gel and the silver – staining one which I have to noticed before I go to extract DNA.
The interested band is about 300 bp and I have to electrophoresis PCR products on polyacrylamide gel because there’re many bands which have their size near the band I need (e.g 350bp, 270bp..). Can I use the QIAEX II Gel extraction Kit of QIAgen for this purpose? Other than this Kit, is there any procedure I can use? (this Kit is too expensive, so if there’s any cheaper way, it’s better)
Please help me, thank for your help!!!

I need a complete end efficient protocol to extract genomic dna from blood sample. For my further research on cloning it is really important that the quality and purity of genomic dna as it will affect the restriction enzyme digestion of genomic dna. I need co-operation from somebody who is working on gene cloning and so on. It will be highly appreciable if anybody provide me a protocol of genomic dna extraction from blood for further cloning process.

This is the protocol we used to extract DNA from a kiwihttp://biotech.biology.arizona.edu/labs/DNA_Kiwifruit_teacher.html