- 基因服務 - cDNA文库 标准的 / 均一化的

cDNA文库 标准的 / 均一化的

标准cDNA文库

用我们独有的技术构建cDNA文库,该技术特征包括:富集全长,高质量的大小分级以及定向克隆的cDNA。有关均一化cDNA文库的信息,请点击这里。

相关服务

 

  1. 保存在液体  或者半固体培养基中的文库,保证能池化和扩增。
  2. 附加一个的双范围文库:获得2个总共万个克隆的亚库。
  3. 根据您的选择范围,每个文库都将有不同大小的插入片段(例如:500bp-2Kb和2Kb-4Kb)。这将使文库的灵活性和代表性达到最大。
  4. 另外,可以提供 克隆的阵列服务。

亮点

  1. 可以得到全长富集的cDNA的合成。
  2. 定向克隆。
  3. 大小分级并连接到载体(改造的pBluescript),以及客户要求的各种自己的载体。
  4. 转化到E. coli DH10B。
  5. 重组子超过99%。
  6. 检测10个克隆来判定插入片段大小(提供电泳照片)。


图1 插入片段大小检测

Insert size determination

Normalized cDNA library

cDNA libraries are produced using our proprietary technology, which features full-length-enriched high quality size-fractionated, and directionally cloned cDNA.

Related Services

  1. Library pooling and amplification is available in liquid or semi-solid medium.
  2. Duo-range libraries feature for an additional fee: Receive 2 sub-libraries of totaling 1.5 million clones.
  3. Each will have a different insert size range of your choice (ex: 500bp-2Kb and 2Kb-4Kb). This maximizes flexibility and representability.
  4. Arraying is available for an additional fee.

Highlights

  1. Representation of abundant transcripts greatly decreased (see Figure 1). Reduction of abundant transcripts is essential for discovery of rare transcripts. For a non-normalized cDNA library, usually 10–20 abundant genes account for at least 20% of the cellular mRNA mass; several hundred genes of medium abundance genes comprise 40–60% of the mRNA mass; several thousand rare genes (<10 mRNA copies per cell) may account for 20–40% of the mRNA mass. Hence, random sequencing of clones from non-normalized cDNA libraries is inefficient, and very costly, for discovering rare transcripts. Decreasing the percentage of these transcripts before sequencing significantly increases the chance for rare gene discovery.
  2. cDNA normalization efficiency is strictly monitored. Apart from the normalization of cDNA population, a parallel normalization is performed. In the parallel normalization, a reporter gene is added to the cDNA population before normalization, as a control. The percentage of this control gene can be easily tested before and after normalization to ensure the quality of normalization. The enrichment of rare and unique sequences is accomplished by using our controlled normalization procedure that reduces the frequency of abundant sequences as much as 400 fold.
  3. Our Normalized cDNA molecules are longer (See Figure 2). Our normalization hybridization method prevents significant loss of average insert size. We perform normalization of cDNA population prior to cloning and library preparation. This prevents size bias against long and otherwise difficult-to-amplify cDNA due to clone bias.
  4. Normalized cDNA molecules are full-length-enriched. We use proprietary method to synthesize full-length enriched cDNA for normalization. DNA libraries rich in clones containing complete coding sequences with 5' and 3' untranslated regions (UTRs) for each transcript in a single cloning step are invaluable for high-throughput transcriptome analysis.
  5. Normalized cDNA molecules are directionally cloned. Directional cloning facilitates bi-directional sequencing, PCR screening and expression.
  6. Low vector background. Bio S&T uses efficient ligation, a high quality vector, as well as electroporation for cloning. As much as 99% of clones have inserts.

Figure 1: Reduction in abundant transcripts after normalization.

Cdna normalized

Figure 2: Insert size determination of a normalized library.

Cdna image

Please note the absence of the redundant bands following the normalization procedure as well as the large size of the cDNAs.