Ra'ayin Sarkar Polymerase, wanda aka fi sani da PCR, yana wakiltar ɗayan manyan ci gaban fasaha a cikin tarihin ilimin halitta. An ƙirƙira shi a cikin 1980s, wannan dabarar ta canza daga tsarin dakin gwaje-gwaje na musamman zuwa kayan aiki na asali da aka yi amfani da su a cikin binciken likitanci, kimiyyar bincike, da binciken kwayoyin halitta. Ta hanyar ƙyale masana kimiyya su ɗauki ɗan ƙaramin samfurin DNA kuma su haɓaka shi zuwa miliyoyin kwafi, PCR ta ba da damar yin nazarin kwayoyin halitta dalla-dalla, gano ƙwayoyin cuta tare da madaidaicin madaidaicin, da kuma gano alamomin kwayoyin halitta waɗanda a baya ba a iya ganin daidaitattun hanyoyin nazari.
Tsarin PCR wata fasaha ce ta dakin gwaje-gwaje da ake amfani da ita don yin kwafi da yawa na takamaiman sashin DNA ta hanyar zagayowar canjin yanayin zafi, wanda ya haɗa da denaturation, annealing, da ƙari, wanda na'urar PCR ta musamman ta sauƙaƙe da kuma DNA polymerase mai ƙarfi.
Fahimtar ƙaƙƙarfan tsarin PCR yana da mahimmanci ga ƙwararrun ƙwararrun ɗakin gwaje-gwaje, masu binciken likita, da masana'antun masana'antu waɗanda ke da hannu a cikin kayan aikin bincike. Yayin da buƙatun gwajin ƙwayoyin ƙwayoyin cuta cikin sauri da daidaito ke ci gaba da haɓakawa a duniya, amincin da Injin PCR ya zama ginshiƙan nasarar sakamakon gwajin gwaji. Wannan labarin yana ba da cikakken jagora ga matakai, yanayin zafi, da buƙatun injina na tsarin PCR don tabbatar da haɓakar DNA mai inganci da ingantaccen sakamakon gwaji.
Teburin Takaitaccen Labarin
| Sashe |
Takaitawa |
| Menene PCR? |
PCR wata dabara ce ta ilimin halitta da ake amfani da ita don haɓaka takamaiman jerin DNA don aikace-aikace daban-daban na ƙasa. |
| Menene ake buƙata don PCR? |
PCR mai nasara yana buƙatar DNA samfuri, masu haɓakawa, nucleotides, DNA polymerase barga, da madaidaicin mai hawan keke. |
| Menene matakai 4 na PCR? |
Tsarin yana biye da jerin ma'ana na ƙaddamarwa, ƙididdigewa, cirewa, da tsawo don ninka abun cikin DNA kowane zagaye. |
| Menene matakan injin PCR? |
Kayan aikin yana sarrafa daidaitattun canjin yanayin zafin jiki, yana tabbatar da halayen ƙwayoyin halitta suna faruwa a daidai lokacin da ake buƙata. |
| Menene zafin da ake amfani da shi don matakin haƙora? |
Ana amfani da yanayin zafi mai yawa, yawanci tsakanin 94°C da 98°C, don karya haɗin gwiwar hydrogen da raba DNA mai ɗaure biyu. |
| Menene ke faruwa a lokacin matakin cirewa? |
A wannan lokacin, ana saukar da zafin jiki don ba da damar firamare su ɗaure musamman zuwa jerin maƙasudin maƙasudin su akan DNA mai ɗaci ɗaya. |
| Menene zafin da ake amfani da shi don matakin tsawo? |
Wannan matakin yawanci yana faruwa a 72°C, mafi kyawun zafin jiki don Taq polymerase don haɗa sabon layin DNA. |
| Menene kwararar zafin PCR? |
Gudun ya ƙunshi saurin hawan keke na tsayi, ƙasa da matsakaicin zafi wanda ke maimaita har sai an kai matakin da ake so. |
Menene PCR?
PCR, ko Polymerase Chain Reaction, hanya ce mai canza yanayin halitta wacce aka ƙera don samar da miliyoyin zuwa biliyoyin kwafi na takamaiman samfurin DNA.
A ainihinsa, PCR yana aiki azaman mai ɗaukar hoto na halitta. Kafin ƙirƙirarsa, haɓaka DNA wani tsari ne na jinkiri kuma mai wahala wanda ya haɗa da cloning DNA cikin ƙwayoyin cuta. Tare da zuwan PCR inji , masu bincike yanzu za su iya ware takamaiman kwayar halitta ko yanki na kwayoyin halitta kuma su kara girman shi a cikin sa'o'i kadan. Wannan ƙarfin yana da mahimmanci saboda yawancin nazarin sunadarai na halittu suna buƙatar adadi mai yawa na DNA don samar da siginar da za a iya aunawa, kuma samfuran halitta galibi suna ba da adadi ne kawai.
Ƙwararren wannan fasaha yana nunawa a cikin nau'o'in aikace-aikace daban-daban a cikin masana'antu daban-daban. A cikin saitunan asibiti, ana amfani da shi don gano nauyin ƙwayar cuta, kamar a cikin COVID-19 ko gwajin HIV. A cikin bincike-bincike, yana ba masu bincike damar gano daidaikun mutane daga ƙananan samfuran kayan halitta. A cikin masana'antu, PCR yana tabbatar da tsabtar kayan abinci da gano kwayoyin halitta da aka gyara. Fahimtar da ka'idoji da farashin fasaha na PCR suna da mahimmanci ga labs da ke neman haɓaka ƙarfin binciken su.
Menene ake buƙata don PCR?
Amsar PCR mai nasara tana buƙatar mahimman sassa guda biyar: samfurin DNA, ƙayyadaddun ƙayyadaddun abubuwa, deoxynucleotide triphosphates (dNTPs), DNA polymerase mai ƙarfi mai zafi (kamar Taq), da ƙwararren buffer bayani.
Samfurin DNA yana aiki azaman ƙirar asali wacce kuke son kwafi. Maɗaukaki gajere ne, guntun DNA na roba waɗanda aka ƙera su don dacewa da farkon da ƙarshen jerin abubuwan da aka yi niyya. Idan ba tare da waɗannan ba, DNA polymerase ba zai san inda zai fara gina sabon madauri ba. dNTPs (A, T, C, da G) su ne tushen ginin da enzyme ke amfani da shi don gina sabon sarkar DNA.
Hakanan mahimmanci shine yanayin da abin ya faru. Mai buffer yana samar da ingantaccen yanayin sinadarai, musamman mayar da hankali kan pH da tattarawar ions na magnesium, waɗanda ke da mahimmancin haɗin gwiwa ga DNA polymerase enzyme. A ƙarshe, aiwatar da aikin motsa jiki na jiki yana buƙatar babban mai yin hawan zafi mai zafi, sau da yawa ana magana da shi azaman na'urar PCR , wanda daidai yake sarrafa saurin canjin zafin jiki da ake buƙata don haifar da kowane mataki na amsawa.
Mabuɗin Abubuwan haɗin PCR
Samfura DNA : Samfurin mai ɗauke da jerin manufa.
DNA Polymerase : Yawancin lokaci Taq polymerase, wanda ya kasance mai aiki a yanayin zafi.
Firimiya : Gaba da juye madauri waɗanda ke ayyana iyakokin haɓakawa.
dNTPs : Tushen nucleotide guda huɗu waɗanda ke aiki azaman 'tawada' don kwafi.
Buffer da ions : Yana kula da ingancin enzymatic da kwanciyar hankali.
Menene matakai 4 na PCR?
Tsarin PCR ya ƙunshi matakan aiki na farko guda huɗu: Ƙaddamarwa, Denaturation, Annealing, da Extension (wanda kuma aka sani da Elongation).
Mataki na farko, Ƙaddamarwa, wani abu ne na lokaci ɗaya inda ɗakin amsa ya kasance mai zafi zuwa babban zafin jiki don tabbatar da cewa DNA polymerase ta cika aiki kuma an kawar da duk wani gurɓataccen abu. Bayan haka, za a fara zagayowar Denaturation, inda aka raba DNA mai ɗaure biyu. Wannan yana biye da Annealing, inda masu farawa suka sami burinsu, kuma a ƙarshe Extension, inda aka haɗa sabon DNA. Wannan zagaye na mataki uku (Denaturation, Annealing, Extension) ana maimaita shi sau 25 zuwa 40.
Saboda adadin DNA ya ninka tare da kowane sake zagayowar nasara, haɓaka yana da girma. Misali, bayan zagayowar 30, kwayar halittar DNA guda daya za a iya juyar da ita sama da kwafi biliyan. Wannan inganci shine abin da ke sa zamani dakin gwaje-gwaje thermal cyclers don haka da muhimmanci ga kimiyyar zamani. Idan ba tare da ɗigon dumama mai sauri da sanyaya da aka samo a cikin injin PCR mai inganci ba , tsarin zai yi jinkirin yin amfani da aiki mai amfani a cikin mahallin bincike mai girma.
Menene matakan injin PCR?
Matakan injin PCR sun haɗa da hawan keke ta atomatik na yanayin zafi ta hanyar daidaitaccen sarrafa lantarki na toshe mai zafi, sarrafa ƙimar ramp, riƙe lokaci, da sanyaya na ƙarshe.
Injin PCR yana aiki ta amfani da abubuwan Peltier don saurin zafi da sanyaya shingen ƙarfe wanda ke riƙe da bututun amsawa. 'Mataki' daga mahangar na'ura sun haɗa da 'Ramp,' wanda shine saurin canzawa tsakanin yanayin zafi, da 'Hold,' wanda shine tsawon lokacin da injin ke kiyaye takamaiman zafin jiki. An ƙera na'urori masu ƙaƙƙarfan ƙaƙƙarfan ƙima don samun saurin haɓakawa don rage lokacin da aka kashe a cikin tsaka-tsaki, wanda ke rage haɗarin ɗauri mara takamaiman ko lalata enzyme.
Software na cikin injin yana ba masu amfani damar tsara ƙayyadaddun ladabi. Wannan ya haɗa da zafi na farko, madaidaicin madaukai na manyan matakai guda uku, da mataki na ƙarshe a yanayin sanyi (yawanci 4 ° C) don adana samfurori har sai mai fasaha zai iya dawo da su. Hanyoyin mu'amala na dijital na zamani akan injin PCR kuma suna ba da izinin saka idanu na ainihin lokacin, tabbatar da cewa ana bin bayanin martabar thermal daidai yadda aka tsara don mafi girman sakewa.
Menene zafin da ake amfani da shi don matakin haƙora?
Matakan denaturation yawanci yana amfani da yanayin zafi tsakanin 94°C da 98°C don sauƙaƙe wargaza haɗin hydrogen tsakanin ma'aunin DNA.
A wannan matsananciyar zafi, tsarin DNA na helix biyu ya zama mara ƙarfi. Haɗin hydrogen wanda ke riƙe nau'ikan adenine-thymine da cytosine-guanine tare suna narkewa tare, yana haifar da nau'ikan DNA guda biyu masu zaman kansu. Wannan muhimmin abu ne mai mahimmanci don matakai na gaba, kamar yadda masu farawa da DNA polymerase enzyme za su iya yin hulɗa tare da samfuri masu ɗauri ɗaya kawai. Idan zafin jiki ya yi ƙasa da ƙasa, DNA ɗin ba zai rabu gaba ɗaya ba, wanda zai haifar da gazawa ko haɓakawa mara inganci.
Koyaya, kiyaye wannan zafin jiki yana buƙatar polymerase DNA mai ƙarfi sosai. Wannan shine dalilin da ya sa gano Taq polymerase, wanda aka keɓe daga ƙwayar cuta mai zafi Thermus aquaticus , ya kasance mai juyi. Za a lalata daidaitattun enzymes a 95°C, amma Taq ya kasance yana aiki. Dakunan gwaje-gwaje dole ne su tabbatar da ɗin su injin PCR yana samar da dumama iri ɗaya a duk rijiyoyin don hana 'rauni mai sanyi' inda za a iya gazawa, wanda shine babban fasalin kayan aiki masu inganci na kwayoyin halitta.
Menene ke faruwa a lokacin matakin cire PCR?
A lokacin matakin cirewa, ana saukar da zafin jiki zuwa tsakanin 50°C da 65°C, yana ba da damar ginshiƙan DNA su ɗaure ga jerin abubuwan da suka dace da su akan samfuran DNA guda ɗaya.
Wannan matakin tabbas shine mafi mahimmancin ɓangaren tsarin PCR. Ƙayyadadden zafin jiki da aka yi amfani da shi ya dogara da zafin narke (Tm) na abubuwan da ake amfani da su. Idan zafin jiki ya yi girma sosai, masu farawa ba za su ɗaure da samfuri ba. Idan ya yi ƙasa da ƙasa, firamare na iya ɗaure jeri-jeru waɗanda kawai 'ɓangare' iri ɗaya ne, wanda zai haifar da haɓakawa mara ƙayyadaddun bayanai da sakamako mara kyau. Dole ne injin PCR ya sami damar buga wannan zafin da aka yi niyya tare da babban matakin daidaito (sau da yawa a cikin 0.1°C).
Tsawon lokacin matakin cirewa yawanci shine 20 zuwa 40 seconds. A cikin wannan takaitacciyar taga, firam ɗin suna kewaya gaurayawan martani ta hanyar motsin ƙwayoyin cuta kuma su ɗauka zuwa wurin da aka nufa. Da zarar abubuwan farko sun toshe, suna samar da wurin farawa don polymerase DNA don fara ƙara nucleotides. Wannan daidaitaccen daidaituwa shine abin da ke ba da damar gano takamaiman maye gurbi ko ƙwayoyin cuta a cikin wani hadadden samfurin nazarin halittu, wanda ya sa saka hannun jari a cikin injunan bincike ƙwararrun fifiko ga labs na asibiti.
Menene zafin da ake amfani da shi don matakin tsawo?
Ana yin matakin tsawaita gabaɗaya a 72°C, wanda shine mafi kyawun zafin aiki don DNA polymerase mai zafi don haɗa sabon madaidaicin DNA.
A 72 ° C, DNA polymerase enzyme yana cikin mafi girman ingancinsa. Yana farawa daga rukunin farko kuma ya fara ƙara dNTPs zuwa ƙarshen 3' na farkon, yana tafiya tare da madaidaicin samfuri. Enzyme 'yana karanta' samfuri kuma yana sanya madaidaicin tushe a cikin sabon layin. Misali, idan samfurin yana da Adenine, polymerase yana ƙara Thymine. Gudun wannan amsa yana da ban sha'awa; Taq polymerase na iya ƙara kusan nau'i-nau'i 1,000 a cikin minti daya.
Tsawon lokacin wannan matakin ya dogara da tsawon ɓangaren DNA da ake kwafi. Idan jerin maƙasudin yana da tsayin tushe guda 1,000, ana iya saita matakin tsawaita na minti ɗaya. Idan makasudin ya fi guntu, za a iya rage lokacin don adana lokacin sarrafawa gaba ɗaya. Tabbatar da injin PCR yana kula da tsayayyen 72°C a duk tsawon wannan lokacin yana da mahimmanci don kammala cikakken tsawon madaurin DNA.
Menene kwararar zafin PCR?
Matsakaicin zafin jiki na PCR yana biye da sake zagayowar yanayin zafi mai zafi, ƙarancin zafi, da tsawaita matsakaicin zafi, ƙirƙirar bayanin martabar zafin rana.
An ƙera wannan kwararar don ƙara girman ci gaban geometric na adadin DNA. A cikin yanayi na yau da kullun, injin yana farawa a 95 ° C na mintuna 2 (Farkon Denaturation), sannan ya shiga madauki: 95°C na daƙiƙa 30, 55°C na daƙiƙa 30, da 72°C na daƙiƙa 60. Wannan madauki yana maimaita sau 30. A ƙarshe, akwai ''Final Extension'' a 72°C na tsawon mintuna 5-10 don tabbatar da cewa duk DNA mai ɗauri ɗaya ya cika madauri biyu kafin injin yayi sanyi zuwa 4°C don ajiya.
Madaidaicin wannan zafin zazzabi yana tasiri kai tsaye ga yawan amfanin ƙasa da tsabtar samfurin PCR. Idan magudanar ta yi rashin daidaituwa, enzyme ɗin na iya rasa aiki ko kuma na'urorin na iya haifar da 'primer dimers,' waɗanda ainihin kayan tarihi ne marasa amfani. Saboda haka, daidaitawa da daidaiton yanayin zafi na injin PCR sune mafi mahimmancin abubuwa ga kowane dakin gwaje-gwaje da ke yin gwajin kwayoyin halitta ko bincike.
Takaitaccen Teburin Gudun Zazzabi
| Mataki |
Yawan Zazzabi |
Manufar |
| Farawa |
94°C – 96°C |
Yana kunna enzymes, yana hana hadaddun DNA. |
| Denaturation |
94°C – 98°C |
Yana raba DNA mai madauri biyu zuwa madauri guda. |
| Annealing |
50 ° C - 65 ° C |
Yana ba da damar firamare su ɗaure zuwa jeri-jeri. |
| Tsawaita |
72°C |
DNA polymerase yana haɗa sabbin igiyoyin DNA. |
| Riƙe Karshe |
4 ° C - 10 ° C |
Adana na ɗan gajeren lokaci na haɓakaccen samfurin. |
Kammalawa
Reaction Sarkar Polymerase wani kayan aiki ne mai kyau kuma mai ƙarfi wanda ya canza yanayin ilimin halittu. Ta bin ƙwararrun matakai na denaturation, annealing, da tsawo, masana kimiyya za su iya buɗe asirin da ke cikin DNA, suna ba da amsoshi ga rikitattun tambayoyin likita da na bincike. Nasarar wannan tsari ya dogara sosai akan ingancin reagents da kuma daidaitaccen injin PCR da ake amfani da shi don aiwatar da zazzagewar zafi.
Ga kowane dakin gwaje-gwaje da ke neman cimma daidaito kuma ingantaccen sakamako, fahimtar abubuwan sarrafa zafin jiki da sarrafa zagayowar yana da mahimmanci. Ko kuna gudanar da bincike na asali ko bincike na asibiti mai girma, zaɓin kayan aiki da bin ingantattun ka'idoji za su ayyana daidaiton aikin ku. Ga masu sha'awar sashin dabaru na kafa dakin binciken kwayoyin halitta, bincika farashi da ƙayyadaddun fasaha na tsarin PCR na zamani shine mataki mai ma'ana na gaba don haɓaka ƙarfin binciken ku.
