■ 制品说明
RACE (Rapid Amplification of cDNA Ends) 是一种获得RNA转录本全长序列的技术。利用RACE技术可以根据转录本中的一小段已知序列获得转录本的5’端 (5’RACE-PCR) 或3’端 (3’RACE-PCR) 序列。
SMARTer® RACE 5’/3’Kit是 SMARTer® RACE cDNA Amplification Kit的升级产品，进一步提高了灵敏度，特异性更好、背景更低。利用该试剂盒合成的一链cDNA可以直接用于5’和3’RACE-PCR，无需任何的接头连接，大大地简化了操作流程，简便易用。SMARTer® RACE 5’/3’Kit扩大了起始RNA样品体积（*至11 ul），并且提高了难扩增基因的扩增效率（如长片段、高GC含量等）。试剂盒采用高效的SeqAmp DNA Polymerase确保PCR扩增效果，同时利用In-Fusion HD Cloning Kit，可以将RACE扩增片段快速、简便地克隆到提供的线性化载体中。 SMARTer® RACE 5’/3’Kit 结合了SMARTer*链cDNA合成技术和强有力的抑制性PCR，显著地减少了RACE实验中的弥散现象，是获得全长cDNA的有效方法。
1. 最便捷的操作
采用SMARTer RACE 技术，可以在一管内完成两步反应。只需很少的操作RNA和新合成cDNA的步骤，整个实验只需4小时。
2. 完整解决方案
SMARTer® RACE 5’/3’Kit提供了除基因特异性引物以外的所有试剂，只需一个试剂盒就可以完成从cDNA合成到RACE扩增片段克隆的全过程，*天即可获得阳性克隆。
3. 只需10 ng总RNA
SMARTer RACE 尤其适用于起始材料有限的情况，如活体组织检查样本、组织分离术样本、针吸活检样本、胚胎组织及病变组织样本等。优化的实验操作，显著地降低了非特异性扩增，这对有限的实验材料尤为重要。
4. 富集具有完整5’端序列的cDNA
专门设计的SMARTer Oligo 优先与新合成的cDNA 的5’端结合，可以富集具有完整5’端序列的cDNA，因此，可以获得全长基因序列或上游调控序列。
5. 不需要RNA预处理
SMARTer RACE方法不需要采用DNase对RNA进行预处理。可以采用总RNA，甚至是含有基因组DNA的RNA材料进行实验。

■ 制品特点
1. 低背景的完整RACE试剂盒
2. SeqAmp DNA Polymerase提供强有力PCR
3. In-Fusion HD Cloning实现RACE产物的快速、简便克隆
4. 只需10 ng总RNA
5. 无需RNA预处理

Introduction
The SMARTer RACE 5’/3’ Kit provides a method for performing both 5’- and 3’-rapid amplification of cDNA ends (RACE). The SMARTer RACE 5’/3’ Kit includes our SMARTer II A Oligonucleotide and SMARTScribe™ Reverse Transcriptase, which provides better sensitivity, less background and higher specificity than previous kits. This powerful system allows you to amplify the complete 5’ sequence of your target transcript from as little as 10 ng of total RNA. The cornerstone of SMARTer RACE cDNA synthesis is SMART® technology, which eliminates the need for problematic adaptor ligation and lets you use first-strand cDNA directly in RACE PCR, a benefit that makes RACE far less complex and much faster (Chenchik et al., 1998). Additionally, the SMARTer RACE Kit exploits Clontech’s technology for suppression PCR & step-out PCR to increase the sensitivity and reduce the background of the RACE reactions. You can use either poly A+ or total RNA as starting material for constructing full-length cDNAs, even of very rare transcripts.
The SMARTer RACE 5’/3’ Kit is an improved version of our original SMARTer RACE cDNA Amplification Kit, designed to accommodate larger RNA input volumes and perform more efficiently on challenging targets (e.g., those that are long, GC-rich, etc.). RACE PCR products are amplified with our highly robust SeqAmp™ DNA Polymerase, and cloned into the linearized pRACE vector with In-Fusion® HD Cloning. The In-Fusion HD Cloning Kit, NucleoSpin Gel and PCR Clean-Up Kit, and Stellar™ Competent Cells are included for your convenience in cloning RACE products.
SMART technology provides a mechanism for generating full-length cDNAs in reverse transcription reactions (Zhu et al., 2001). This is made possible by the joint action of the SMARTer II A Oligonucleotide and SMARTScribe Reverse Transcriptase. When the SMARTScribe RT reaches the 5’ end of the RNA, its terminal transferase activity adds a few additional nucleotides to the 3’ end of the first-strand cDNA (Figure 1).
Figure 1. Mechanism of SMARTer cDNA synthesis. First-strand cDNA synthesis is primed using a modified oligo (dT) primer. After SMARTScribe Reverse Transcriptase (RT) reaches the end of the mRNA template, it adds several nontemplated residues. The SMARTer II A Oligonucleotide anneals to the tail of the cDNA and serves as an extended template for SMARTScribe RT.
The SMARTer II A Oligonucleotide contains a terminal stretch of modified bases that anneal to the extended cDNA tail, allowing the oligo to serve as a template for the RT. SMARTScribe RT switches templates from the mRNA molecule to the SMARTer oligo, generating a complete cDNA copy of the original RNA with the additional SMARTer sequence at the end. Since the template switching activity of the RT occurs only when the enzyme reaches the end of the RNA template, the SMARTer sequence is typically only incorporated into full-length, first-strand cDNAs. This process guarantees that the use of high quality RNA will result in the formation of a set of cDNAs that have a maximum amount of 5’ sequence (Table I).