Help Finding Rare Sequences

If you suspect that your target is rare and likely to be poorly expressed compared with more abundant messages, consider using our normalization and subtraction services. Proprietary, self-subtraction, or tissue-tissue subtraction techniques reduce abundant sequences 10- to 100-fold (Figure 1 and Table 1), making it easier to find rare or low-expressed targets. The resulting normalized library enhances discovery of novel sequences and needs less sequencing—especially important for high-throughput applications.  Our normalized/subtracted libraries achieve:

  • No significant loss of average insert size
  • Low vector background
  • >3 x 106 clones

Reduction Abundant Clones

Figure 1. Reduction of abundant clones in normalized compared with non-normalized libraries.

Table 1. Reduction of abundant clones and preservation of insert sizes.

cDNA library Before normalization After normalization Probe used for QC Fold reduction after normalization
 Average insert size (kb)% recombinationAverage insert size (kb)% recombination  
Mouse Testis1.71001.5792EF-1a62
Bovine Pooled1.7961.7296EF-1a16
Dog Lymphocyte2.41001.75100ß -actin48
Salmon pooled1.9961.6696EF-1a46
Cotton Aphid1.81001.7196ß -actin20
Crab Gill1.11001.26100Arginine kinase30
Castor Bean1.5961.2896670-12S138

For more information or to order a service, call 800.955.6288x2 or e-mail