Polymerase saw cov tshuaj tiv thaiv (PCR) yog ib txoj hauv kev ntawm molecular biology uas tso cai rau koj los txheeb xyuas qhov me me ntawm deoxyribonucleic acid (DNA) hauv cov khoom siv lom neeg, ntau qhov tseeb, qee qhov tawg ntawm nws, thiab muab lawv ntau zaus. Tom qab ntawd lawv raug txheeb xyuas pom los ntawm gel electrophoresis. Cov tshuaj tiv thaiv tau tsim nyob rau xyoo 1983 los ntawm K. Mullis thiab suav nrog hauv cov npe ntawm cov kev tshawb pom zoo tshaj plaws ntawm xyoo tas los no.
Dab tsi yog cov txheej txheem ntawm PCR
Txhua cov txheej txheem yog raws li lub peev xwm ntawm nucleic acids rau nws tus kheej replicate, uas nyob rau hauv cov ntaub ntawv no yog nqa tawm nyob rau hauv ib tug kuaj. DNA reproduction yuav tsis pib nyob rau hauv ib cheeb tsam ntawm lub molecule, tab sis tsuas yog nyob rau hauv cov cheeb tsam nrog ib tug tej yam nucleotide ib theem zuj zus - pib fragments. Txhawm rau kom cov tshuaj tiv thaiv polymerase pib, primers (lossis DNA probes) xav tau. Cov no yog cov tawg luv luv ntawm DNA saw nrog cov nucleotide sib lawv liag. Lawv yog cov complementary (piv txwv li, sib thooj) rau cov cheeb tsam pib ntawm tus qauv DNA.
Tau kawg, txhawm rau tsim cov primers, cov kws tshawb fawb yuav tsum kawm cov nucleotide sib lawv liag ntawm nucleic acid koom nrog hauv cov txheej txheem. Nws yog cov DNA sojntsuam uas muab qhov tshwj xeeb ntawm cov tshuaj tiv thaiv thiab nws qhov pib. Cov tshuaj tiv thaiv kab mob polymerase yuav tsis mus yog tias tsawg kawg ib qho molecule ntawm DNA xav tau tsis pom hauv cov qauv. Feem ntau, cov primers saum toj no, ib txheej ntawm nucleotides, hluav taws kub-resistant DNA polymerase yog tsim nyog rau cov tshuaj tiv thaiv tshwm sim. Lub tom kawg yog ib qho enzyme - lub catalyst rau kev sib txuas ntawm cov nucleic acid molecules tshiab raws li cov qauv. Tag nrho cov tshuaj no, suav nrog cov khoom siv roj ntsha uas tsim nyog los kuaj DNA, tau muab tso rau hauv cov tshuaj tiv thaiv sib xyaw (kev daws teeb meem). Nws tau muab tso rau hauv lub ntsuas kub tshwj xeeb uas ua kom cua sov sai thiab txias rau lub sijhawm muab - lub voj voog. Feem ntau muaj 30-50.
qhov kev tawm tsam no ua haujlwm li cas
Nws cov ntsiab lus nyob rau hauv qhov tseeb tias thaum lub sij hawm ib lub voj voog cov primers tau txuas mus rau qhov xav tau ntawm DNA, tom qab ntawd nws tau muab ob npaug rau hauv qhov kev txiav txim ntawm enzyme. Raws li qhov tshwm sim DNA strands, tshiab thiab tshiab zoo ib yam ntawm cov molecule yog synthesized nyob rau hauv lub tom ntej cycles.
Cov tshuaj tiv thaiv kab mob polymerase tau ua ntu zus, nws cov theem hauv qab no yog qhov txawv. Thawj yog tus cwj pwm los ntawm ob npaug ntawm cov khoom lag luam thaum lub sij hawm txhua qhov cua sov thiab cua txias. Hauv theem ob, cov tshuaj tiv thaiv qeeb, vim tias cov enzyme raug puas tsuaj thiab tseem poob haujlwm. Tsis tas li ntawd, cov reserves ntawm nucleotides thiab primers yog depleted. Nyob rau theem kawg - toj siab - cov khoom tsis sib sau,vim cov reagent tawm lawm.
siv qhov twg
Undoubtedly, cov tshuaj tiv thaiv polymerase saw pom cov ntawv thov dav tshaj plaws hauv tshuaj thiab kev tshawb fawb. Nws yog siv nyob rau hauv dav dav thiab ntiag tug biology, veterinary tshuaj, khw muag tshuaj thiab txawm ecology. Ntxiv mus, nyob rau tom kawg lawv ua qhov no los saib xyuas cov khoom noj khoom haus zoo thiab cov khoom ib puag ncig. Cov tshuaj tiv thaiv kab mob polymerase tau nquag siv hauv kev coj ua pov thawj kom paub meej tias leej txiv thiab txheeb xyuas tus neeg. Nyob rau hauv forensics, raws li zoo raws li nyob rau hauv paleontology, cov txheej txheem no feem ntau yog tib txoj kev tawm, vim hais tias feem ntau tsawg heev DNA muaj nyob rau kev tshawb fawb. Tau kawg, txoj kev tau pom ib daim ntawv thov dav heev hauv cov tshuaj siv tau. Nws yog qhov xav tau hauv thaj chaw xws li caj ces, kab mob sib kis thiab kab mob oncological.
