Iyunithi engu-1 (U) Umsebenzi weTaq Platinum DNA Polymerase uchazwa njengenani le-enzyme edingekayo ukufaka i-10 nmol deoxynucleotides ezintweni ezingenayo i-acid ku-74 ° C kungakapheli imizuzu engama-30 kusetshenziswa isidoda se-salmon DNA njenge template / primer.
Ukuhlanzeka ngokutholwa kwe-SDS-PAGE kungaphezu kwama-99%; Awukho umsebenzi we-nuclease wangaphandle otholakele; Uhlobo lwekhophi elilodwa ku-genome yomuntu lungakhuliswa ngempumelelo; Akukho ukushintsha komsebenzi okuphawulekayo lapho kugcinwa ekamelweni lokushisa isonto elilodwa.
Inomsebenzi wokukhululwa ngaphandle kuka-5'-3 "nomsebenzi ongu-3'-5" wokuxolelwa, futhi ukuthembeka kwayo kuseceleni kwePfu polymerase. Isivinini sokunweba seTaq Platinum Polymerase sishesha kunePfu polymerase futhi ukusebenza kahle kwe-amplification kuphezulu. Imikhiqizo ye-PCR ingaboshelwa ngqo emaphethelweni abuthuntu noma yenziwe ngevektha ye-TA. Uma ukusebenza kahle kwe-cloning kudinga ukwenziwa ngcono, kunconywa ukuthi kuhlanzwe kuqala bese kufakwa ama-3'-dA overhangs ngaphambi kokuhlangana ku-vector ye-TA.
I-One-tube Taq Platinum MasterMix (Isitifiketi Sikazwelonke Semikhiqizo Ephezulu)
■ I-Taq Platinum MasterMix ithuthukise ukucaciswa nokuzwela kokuphendula kwe-PCR futhi ingakhulisa izifanekiso eziyinkimbinkimbi ngokuqukethwe okuphezulu kwe-GC, ukwakheka kwesibili nokunye okunjalo. Amakhophi ama-2 aphansi wethempulethi ekhonjiwe angakhuliswa, aqinisekise imiphumela yokulinga enembe kakhulu.
■ Ifomula eyingqayizivele ye-Taq Platinum MasterMix yenza lonke uhlelo lokuphendula luzinze kakhulu, futhi umsebenzi ngeke uthinteke ukubanda okubandayo okuphindaphindiwe noma ukugcinwa kwesikhathi eside ngo-4 ° C.
■ Isixazululo esihlanganisiwe nesisebenza kahle se-PCR esilungisiwe singenza ukusebenza kusheshe futhi kube lula, kunciphise kakhulu umfutho wabasebenzi nephutha lesampula. Isithuthukisi se-PCR esisebenza kahle kanye ne-optimizer nakho kufakiwe ekuxubeni, okunciphisa izidingo ezimweni ze-PCR.
■ Lo mkhiqizo unezinhlelo zombili eziqukethe udayi nezingenawo udayi. Imikhiqizo ye-MasterMix equkethe udayi ingaxhunyaniswa ngokuqondile ngemuva kwe-PCR, ngaphandle kokungeza i-buffer yokulayisha.
Ingangena esikhundleni sePfu polymerase ukukhulisa imikhiqizo yokwethembeka ephezulu kusuka kuzifanekiso eziyinkimbinkimbi ezinjengama-genomes, futhi ifanele izinhlelo zokusebenza ezifana nokuhlanganiswa kwezakhi zofuzo, ukuguqulwa okuqondene nendawo nokuhlaziywa kwe-nucleotide polymorphism (SNP) eyodwa, njll.
Okumele kuqashelwe Ekwakheni ama-PCR Primers:
Ubude bokuqala buvame ukuba ngama-20-25 mer. Kodwa-ke, lapho wenza ucezu olude lwe-PCR, ubude be-primer kufanele benyuswe bube ngu-30-35 mer.
■ Akukho ukumatanisa okuhambisanayo phakathi kwama-primers amabili, ikakhulukazi ezisekelweni ezi-3 zokugcina ekugcineni kwe-3.
■ Okuqukethwe kwe-GC kufanele kube ngama-50-60%, futhi kugweme i-GC ecebile yendawo noma i-AT. Ukuze wenze i-primer ne-template zibophe kahle, gwema isakhiwo se-AT ekugcineni kwe-3.
■ Gwema isiqalo sokwakha isakhiwo sesibili.
■ Khetha izinhlobo ezimbili ezinamazinga okushisa we-Tm asondelene.
Ukubalwa kwe-Tm Value of Primers ye-PCR:
■ Lapho i-primer ingaphansi kwama-20 mer: Tm = 2 ° C × (A + T) + 4 ° C × (G + C).
■ Lapho i-primer ingaphezu kwama-20 mer: Tm = 81.5 + 0.41 × (GC%) - 600 / L, lapho L ubude be-primer.
Set Setha izinga lokushisa lokunamathisela ku- (Tm-5) ° C.
Ukuhlungwa kokugcina okufanelekile kungakhethwa phakathi kuka-0.1 μM no-1.0 μM. Ukwehliswa kwesilinganiso esiphansi kakhulu kuholela ekukhiqizweni okuphansi kwemikhiqizo yokukhulisa, kuyilapho ukuphakama okukhulu kakhulu kuthambekele ekukhulisweni okungacacisiwe. Imvamisa, lapho inani le-template le-DNA likhulu noma liyinkimbinkimbi ye-template ye-DNA (efana ne-genome DNA yomuntu) isetshenziswa njengethempulethi, ukuhlushwa kokuqala kufanele kube phansi. Lapho inani le-template le-DNA lincane noma lilula le-template ye-DNA (isib.
Yonke imikhiqizo ingenziwa ngezifiso i-ODM / OEM. Ngemininingwane,sicela uchofoze i-Customized Service (ODM / OEM)
Sebenzisa i-genomic DNA njengethempulethi ukukhulisa ucezu lwe-1 kb. Ngemuva kokuphendula kwe-PCR, thatha u-5 μl ukuthola ukutholwa kwe-electrophoresis. |
Isifanekiso se-A-1
■ Ithempulethi iqukethe ukungcola kwamaprotheni noma ama-Taq inhibitors, njll. - —Purify DNA template, susa ukungcola kwamaprotheni noma ukhiphe i-DNA template ngamakhithi okuzihlanza.
■ Ukwehlukaniswa kwethempulethi akuphelele ——Kwandisa ngokufanele ukushisa kwama-denaturation futhi kwandise isikhathi se-denaturation.
■ Ukuwohloka kwesifanekiso ——Lungisa kabusha ithempulethi.
I-A-2 Primer
■ Izinga eliphansi lama-primers ——Re-synthesize the primer.
■ Ukuwohloka kwe-Primer ——Faka ama-primer primer aphezulu abe yivolumu encane yokulondolozwa. Gwema ukubanda okuningi nokuncibilikisa noma ukugcina isikhathi eside u-4 ° C.
■ Idizayini engalungile yama-primers (isb. Ubude be-primer abwenele, i-dimer eyakhiwe phakathi kwama-primers, njll.) -Redesign primers (gwema ukwakheka kwe-primer dimer nesakhiwo sesibili)
I-A-3 Mg2+ukuhlushwa
■ Mg2+ ukuminyana kuphansi kakhulu —— Khulisa ngokufanele uMg2+ ukuhlushwa: Lungiselela iMg2+ ukugxila ngochungechunge lokuphendula kusuka ku-1 mM kuye ku-3 mM ngesikhawu esingu-0.5 mM ukuthola iMg efanelekile2+ ukugxila kuthempulethi ngayinye nakuqala.
Ukushisa kwe-A-4 Annealing
The Ukushisa okuphezulu kokunciphiswa komthelela kuthinta ukubopha kwe-primer ne-template. - - Nciphisa ukushisa okunciphisayo futhi wenze ngcono isimo nge-gradient ka-2 ° C.
Isikhathi se-A-5 Sesandiso
■ Isikhathi esifushane sokunweba — - Khulisa isikhathi sokunweba.
I-Phenomena: Amasampula amabi nawo akhombisa amabhendi wokulandelana okuqondiwe.
Ukungcola kwe-A-1 kwe-PCR
■ Ukungcola kwesiphambeko sokulandelana okuqondiwe noma imikhiqizo yokukhulisa amandla ——Nakekela ukuthi ungafaki isampuli ngesampula equkethe ukulandelana kwethagethi kusampula engeyinhle noma uchithe iphume kushubhu le-centrifuge. Ama-reagents noma okokusebenza kufanele kwenziwe ngokuzenzakalela ukuqeda ama-nucleic acid akhona, futhi ubukhona bokungcola kufanele kunqunywe ngokuhlolwa kokulawulwa okungalungile.
■ Ukungcola okuyisenzo ——Faka ama-reagents bese uwagcina lapho kushisa okuncane.
I-A-2 Primer
■ Mg2+ ukuminyana kuphansi kakhulu —— Khulisa ngokufanele uMg2+ ukuhlushwa: Lungiselela iMg2+ ukugxila ngochungechunge lokuphendula kusuka ku-1 mM kuye ku-3 mM ngesikhawu esingu-0.5 mM ukuthola iMg efanelekile2+ ukugxila kuthempulethi ngayinye nakuqala.
■ Idizayini yokuqala engafanele, nokulandelana kwempokophelo kune-homology ngokulandelana okungeyona eyenhloso. ——Kwakha kabusha ama-primers.
I-Phenomena: Amabhendi wokukhulisa we-PCR awahambelani nosayizi olindelekile, kungaba mikhulu noma mincane, noma kwesinye isikhathi womabili amabhendi okukhulisa kanye namaqembu wokukhulisa angaqondile.
I-A-1 Primer
■ Ukucaciswa okungafanelekile kokuqala
——Kwakha kabusha isiqalo.
■ Ukuhlungwa kwe-primer kuphakeme kakhulu — -Kwandisa ngokufanele ukushisa kwe-denaturation futhi kwandise isikhathi se-denaturation.
I-A-2 Mg2+ ukuhlushwa
■ UMg2+ ukuminyana kuphakeme kakhulu —— Nciphisa kahle ukuhlushwa kwe-Mg2 +: Lungiselela iMg2+ ukugxila ngochungechunge lokuphendula kusuka ku-1 mM kuye ku-3 mM ngesikhawu esingu-0.5 mM ukuthola iMg efanelekile2+ ukugxila kuthempulethi ngayinye nakuqala.
I-A-3 Thermostable polymerase
■ Inani le-enzyme eyeqile - - Nciphisa inani le-enzyme ngokufanele ngezikhathi ezithile zika-0.5 U.
Ukushisa kwe-A-4 Annealing
■ Izinga lokushisa elinciphisayo liphansi kakhulu ——Kwandisa ngokufanele ithempelesha yokuncisha noma ukusebenzisa indlela yokuncisha izigaba ezimbili
Imijikelezo ye-A-5 PCR
■ Imijikelezo eminingi kakhulu ye-PCR —— Nciphisa inani lemijikelezo ye-PCR.
I-A-1 Primer—— Okucacile okungekuhle—— Yakha kabusha i-primer, shintsha ukuma nobude be-primer ukuthuthukisa ukucaciswa kwayo; noma wenze i-PCR ehlanganisiwe.
I-A-2 Template DNA
——Isifanekiso asihlanzekile —Hlanza ithempulethi noma ukhiphe i-DNA enezikhwama zokuhlanzwa.
I-A-3 Mg2+ ukuhlushwa
- —Mg2+ ukugxilisa ingqondo kuphakeme kakhulu ——Ukunciphisa kahle uMg2+ ukuhlushwa: Lungiselela iMg2+ ukugxila ngochungechunge lokuphendula kusuka ku-1 mM kuye ku-3 mM ngesikhawu esingu-0.5 mM ukuthola iMg efanelekile2+ ukugxila kuthempulethi ngayinye nakuqala.
I-A-4 dNTP
—— Ukuhlungwa kwama-dNTP kuphakeme kakhulu —— Nciphisa ukuminyana kwe-dNTP ngokufanele
Ukushisa kwe-A-5 Annealing
——Ukushisa okuncishisayo okuphansi impela —— Kukhuphula kahle ukushisa okuncishisayo
Imijikelezo engu-A-6
—Imijikelezo eminingi kakhulu —— Yandisa inani lomjikelezo
Isinyathelo sokuqala ukukhetha i-polymerase efanelekile. I-Taq polymerase ejwayelekile ayikwazi ukufundwa ngenxa yokuntuleka komsebenzi we-3'-5 'wokuxolelwa, futhi ukungafani kahle kuzonciphisa kakhulu ukusebenza kwezingcezu. Ngakho-ke, i-Taq polymerase ejwayelekile ayikwazi ukukhulisa ngempumelelo izingcezu ezihlosiwe ezinkulu kune-5 kb. I-Taq polymerase enokuguqulwa okukhethekile noma okunye ukuthembeka okuphezulu kwe-polymerase kufanele kukhethwe ukuthuthukisa ukusebenza kahle kokunwetshwa nokuhlangabezana nezidingo zokukhulisa isiqeshana eside. Ngaphezu kwalokho, ukukhuliswa kwezingcezu ezinde kudinga nokulungiswa okuhambisanayo komklamo wokuqala, isikhathi sokudlulisa isikhathi, isikhathi eseluliwe, i-pH yesikhondlakhondla, njll. Ngokuvamile, ama-primers ane-18-24 bp angaholela esivunweni esingcono. Ukuvikela ukulimala kwethempulethi, isikhathi sokudonswa kwenani elingu-94 ° C kufanele sehliswe lifike kumasekhondi angama-30 noma ngaphansi ngomjikelezo ngamunye, nesikhathi sokukhuphuka kwamazinga okushisa siye ku-94 ° C ngaphambi kokukhulisa amandla kufanele kube ngaphansi kweminithi elilodwa. Ngaphezu kwalokho, ukusetha izinga lokushisa lokunwebeka cishe ku-68 ° C nokuklama isikhathi sesandiso ngokuya ngesilinganiso se-1 kb / min kungaqinisekisa ukukhuliswa okusebenzayo kwezingcezu ezinde.
Izinga lephutha lokukhulisa i-PCR lingehliswa ngokusebenzisa ama-polymerase e-DNA ahlukahlukene ngokuthembeka okuphezulu. Kuwo wonke ama-polymerase eTaq DNA atholakele kuze kube manje, i-Pfu enzyme inezinga lephutha eliphansi kakhulu nokuthembeka okuphezulu (bheka ithebula elihlanganisiwe). Ngaphezu kokukhethwa kwe-enzyme, abacwaningi bangaqhubeka banciphise izinga lokuguqulwa kwe-PCR ngokwenza ngcono izimo zokuphendula, kufaka phakathi ukwakheka kwe-buffer, ukuminyana kwe-polymerase esetshenziswayo nokwandisa inombolo yomjikelezo we-PCR.
Kusukela yasungulwa, imboni yethu ibilokhu ithuthukisa imikhiqizo esezingeni lomhlaba yokuqala ngokunamathela esimisweni
wekhwalithi kuqala. Imikhiqizo yethu izuze idumela elihle kakhulu embonini futhi ithembekile phakathi kwamakhasimende amasha namadala ..