问题 单项选择题

对于极微量的靶序列的扩增可以采用的PCR技术是()

A.通用引物-PCR方法(generalprimer-media-tedPCR,GP-PCR)

B.多重PCR(multiplexPCR)

C.套式PCR(nestedprimers-polymerasechainreaction,NP-PCR)

D.AP-PCR方法(arbitrarilyprimedPCR)

E.原位PCR技术(insituPCR,ISP(R)

答案

参考答案:C

解析:通用引物一PCR方法利用合成的通用引物,进行PCR反应,具有广谱检测优势,阳性率远远高于特异性引物PCR法,便于临床诊断中大量标本筛检,大范围内的流行病学调查。多重PCR则是用几对引物在同一个PCR反应体系中进行扩增。这样可以同时扩增出几个不同专一靶区域的片段。套式PCR要设计"外引物"及"内引物"两对引物进行连续两次PCR,可以提高PCR检测的灵敏度和特异性。对于极微量的靶序列,一次扩增难以取得满意的效果,应用套式PCR技术可获得良好的结果。AP-PCR方法,可快速地从两个或更多的个体组织细胞中分离出差异基因或基因差异表达产物。原位PCR技术能在细胞涂片和组织切片上对待检的低拷贝或单拷贝数基因进行扩增。

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                                               Editor (编辑) Wanted
Editor needed to direct the work of new music magazine. At least two years editorial
experience needed. Hours: 8:00 AM to 5:00 PM. Some overtime required. Send your
personal information to:
P.O. Box 213, Fairview, IN. 46243.

                                                   Bank Manager
Town Bank is looking for a bank manager to head its downtown branch (分行). A person
with 5+ years experience. Working Hours: 8:30 AM to 5:30 PM. Mail to< newbank@gol.com >
for more information.

                                                 Teachers Needed
Language Centre needs experienced teachers for its new English teaching program. PT/FT
(兼/专职) positions available. No more than 25 teaching hours a week. AM/PM changes.
Teachers with background in computer skills preferred (优先). Tel: 567-1243.

                                                   Nurses in Need
Child Care Centre serves children from 3 to 6 years of age. It provides care five days
a week, and is open about ten hours a day. It is in great need of nurses with the
experience of guiding (指导) different activities such as indoor and outdoor games.
Call 432-3745 or visit our website: www.vps. msu edu/efcr.
1. Person with _____ of experience is needed to head the bank.
[ ]
A. at least two years
B. twenty - five years
C. three to six years
D. more than five years
2. You should work for _____ if you become an editor of the magazine.
[ ]
A. just nine hours a day
B. no less than nine hours a day
C. about ten hours a day
D. less than 25 hours a week
3. If you want to be a teacher, you can _____ for more information.
[ ]
A. call 567-1243
B. mail to< newbank@gol.com >
C. phone 432 - 3745
D. write to P. O. Box 213, Fairview
4. You need to have the experience of directing different activities to _____.
[ ]
A. be an editor of the music magazine
B. head a bank branch of Town Bank
C. teach English in Language Centre
D. work as a nurse in Child Care Centre
5. Which of the following is NOT true according to the passage?
[ ]
A. Child Care Centre doesn't provide care for children of all ages.
B. Teachers are wanted to teach English in the Language Centre.
C. One with computer skills will be preferred to head the bank.
D. Your own information is available for the position of the editor.
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