PCR, ko polymerase chain reaction, wata dabara ce da ake amfani da ita don haɓaka jerin DNA.Kary Mullis ne ya fara haɓaka shi a cikin 1980s, wanda aka ba shi lambar yabo ta Nobel a ilmin sunadarai a 1993 saboda aikinsa.PCR ta yi juyin juya halin kwayoyin halitta, yana bawa masu bincike damar haɓaka DNA daga ƙananan samfurori kuma suyi nazarin shi daki-daki.
PCR tsari ne mai mataki uku wanda ke faruwa a cikin injin zazzage mai zazzagewa, injin da zai iya canza yanayin zafi da sauri.Matakan uku sune denaturation, annealing, da tsawo.
A mataki na farko, denaturation, DNA mai madauri biyu yana zafi zuwa babban zafin jiki (yawanci a kusa da 95 ° C) don karya haɗin hydrogen da ke riƙe da igiyoyi biyu tare.Wannan yana haifar da ƙwayoyin DNA guda biyu masu ɗauri ɗaya.
A mataki na biyu, annealing, ana saukar da zafin jiki zuwa kusan 55°C don ba da damar abubuwan da ake buƙata su ɓata zuwa jerin abubuwan da suka dace akan DNA mai ɗaci ɗaya.Maƙasudai gajeru ne na DNA waɗanda aka ƙera don dacewa da jerin abubuwan sha'awa akan DNA ɗin da aka yi niyya.
A mataki na uku, tsawo, ana ɗaga zafin jiki zuwa kusan 72°C don ba da damar Taq polymerase (wani nau'in DNA polymerase) don haɗa sabon layin DNA daga abubuwan da aka tsara.Taq polymerase an samo shi ne daga kwayar cutar da ke rayuwa a cikin maɓuɓɓugar ruwa mai zafi kuma yana iya jure yanayin zafi da ake amfani da shi a cikin PCR.
Bayan zagaye ɗaya na PCR, sakamakon shine kwafi biyu na jerin DNA da aka yi niyya.Ta maimaita matakai uku don yawan zagayowar (yawanci 30-40), adadin kwafin jerin DNA ɗin da aka yi niyya na iya ƙarawa da yawa.Wannan yana nufin cewa ko da ƙaramin adadin farkon DNA ana iya ƙarawa don samar da miliyoyin ko ma biliyoyin kwafi.
PCR yana da aikace-aikace masu yawa a cikin bincike da bincike.Ana amfani da shi a cikin kwayoyin halitta don nazarin aikin kwayoyin halitta da maye gurbi, a cikin binciken bincike don nazarin shaidar DNA, a cikin cututtukan cututtuka don gano gaban ƙwayoyin cuta, da kuma ganewar asali don tantance cututtuka na kwayoyin halitta a cikin 'yan tayin.
Hakanan an daidaita PCR don amfani a cikin bambance-bambance daban-daban, kamar PCR mai ƙididdigewa (qPCR), wanda ke ba da damar auna adadin DNA da juyar da PCR (RT-PCR), wanda za'a iya amfani dashi don haɓaka jerin RNA.
Duk da aikace-aikacen sa da yawa, PCR yana da iyaka.Yana buƙatar sanin jerin abubuwan da aka yi niyya da ƙira na abubuwan da suka dace, kuma yana iya zama mai saurin kuskure idan ba a inganta yanayin amsawa daidai ba.Koyaya, tare da ƙirar gwaji da kisa a hankali, PCR ya kasance ɗayan kayan aiki mafi ƙarfi a cikin ilimin halitta.
Lokacin aikawa: Fabrairu-22-2023