Nucleic acid tau muab faib ua deoxyribonucleic acid (DNA) thiab ribonucleic acid (RNA), ntawm cov RNA tuaj yeem muab faib ua ribosomal RNA (rRNA), tub txib RNA (mRNA) thiab hloov RNA (tRNA) raws li kev ua haujlwm sib txawv.

DNA feem ntau yog concentrated nyob rau hauv lub nucleus, mitochondria thiab chloroplasts, thaum RNA feem ntau faib nyob rau hauv lub cytoplasm.

Vim hais tias purine bases thiab pyrimidine bases tau conjugated ob daim ntawv cog lus hauv nucleic acids, nucleic acids muaj cov yam ntxwv ntawm kev nqus ultraviolet. Kev nqus ultraviolet ntawm DNA sodium ntsev yog nyob ib puag ncig 260nm, thiab nws qhov nqus tau yog qhia raws li A260, thiab nws yog nyob ntawm qhov nqus nqus ntawm 230nm, yog li ultraviolet spectroscopy tuaj yeem siv tau. Nucleic acids yog quantitatively thiab qualitatively txiav txim los ntawm ib tug luminometer.

Nucleic acids yog ampholytes, uas sib npaug rau polyacids. Nucleic acids tuaj yeem sib cais rau hauv cov anions los ntawm kev siv nruab nrab lossis alkaline buffers, thiab muab tso rau hauv qhov hluav taws xob kom txav mus rau qhov anode. Qhov no yog lub hauv paus ntsiab lus ntawm electrophoresis.

Nucleic acid extraction thiab purification cov cai thiab cov cai

1. Ua kom muaj kev ncaj ncees ntawm nucleic acid thawj cov qauv

2. Tshem tawm cov kab mob ntawm lwm cov molecules (xws li tsis suav nrog RNA cuam tshuam thaum rho DNA)

3. Yuav tsum tsis txhob muaj cov kuab tshuaj organic thiab cov ntsiab lus siab ntawm cov hlau ions uas inhibit enzymes hauv cov qauv nucleic acid.

4. Txo cov tshuaj macromolecular xws li cov proteins, polysaccharides thiab lipids kom ntau li ntau tau

Nucleic acid extraction thiab purification txoj kev

1. Phenol/chloroform extraction method

Nws tau tsim nyob rau hauv 1956. Tom qab kho cov cell tawg kua los yog cov ntaub so ntswg homogenate nrog phenol / chloroform, cov nucleic acid Cheebtsam, feem ntau DNA, yog yaj nyob rau hauv lub aqueous theem, lipids yog nyob rau hauv lub organic theem, thiab cov proteins nyob nruab nrab ntawm ob. theem.

2. Dej cawv

Ethanol tuaj yeem tshem tawm cov hydration txheej ntawm nucleic acid thiab nthuav tawm cov pab pawg tsis zoo phosphate, thiab cov khoom muaj txiaj ntsig zoo xws li NA﹢ tuaj yeem ua ke nrog phosphate pawg los tsim cov precipitate.

3. Chromatographic kem txoj kev

Los ntawm cov khoom siv tshwj xeeb silica-raws li adsorption, DNA tuaj yeem raug adsorbed tshwj xeeb, thaum RNA thiab cov protein tuaj yeem hla tau zoo, thiab tom qab ntawd siv cov ntsev thiab pH qis los khi nucleic acid, thiab elute nrog ntsev thiab pH siab kom cais thiab ntxuav cov nucleic. kua qaub.

4. Thermal cracking alkali txoj kev

Alkaline extraction tsuas yog siv qhov sib txawv topological ntawm covalently kaw ncig plasmids thiab linear chromatin cais lawv. Nyob rau hauv alkaline tej yam kev mob, denatured proteins yog soluble.

5. Boiling pyrolysis txoj kev

Cov tshuaj DNA yog kho cua sov kom tau txais txiaj ntsig zoo ntawm cov khoom ntawm cov kab DNA molecules kom cais cov DNA tawg ntawm cov precipitate tsim los ntawm denatured proteins thiab cellular khib nyiab los ntawm centrifugation.

6. Nanomagnetic hlaws txoj kev

Siv nanotechnology los txhim kho thiab hloov kho qhov chaw ntawm superparamagnetic nanoparticles, superparamagnetic silicon oxide nano-magnetic hlaws yog npaj. Cov hlaws sib nqus tuaj yeem paub meej thiab zoo khi rau nucleic acid molecules ntawm microscopic interface. Siv cov khoom superparamagnetic ntawm silica nanospheres, nyob rau hauv qhov kev txiav txim ntawm Chaotropic ntsev (guanidine hydrochloride, guanidine isothiocyanate, thiab lwm yam) thiab sab nraud magnetic teb, DNA thiab RNA raug cais tawm ntawm cov ntshav, tsiaj cov nqaij, zaub mov, kab mob kab mob thiab lwm yam qauv.