Learn more about the properties of your protein
Gene libraries are a pool of DNA sequences, based on a single input sequence, harbouring mutations at defined positions.
Combinatorial Gene Libraries are very useful for high-throughput screening and allow to
- Optimise the binding characters of antibodies
- Optimise protein properties (e.g. protein stability / activity)
- Optimise for improved expression of your protein
- Find the best DNA sequence for improved protein binding
- Improve ribozyme activity
Choose between two different kinds of Combinatorial Libraries:
In addition to Combinatorial Libraries Eurofins also other library tyes. Read more
Complexity of a library
Cloned libraries from Eurofins are delivered with a maximum diversity of 108 variants. If too many wobble positions are selected it is even not statistically possible to deliver all clones. Here are some examples:
...GCT NNN AGC T...
- 64 possible variants (4x4x4 = 43)
- All amino acids at one position
...GCT NNK AGC T...
- 32 possible variants (21x42)
- NNK = all amino acids excluding 2 stop codons
- Reduced complexity
...GCT NNN NNN NNN NNN NNN AGC T...
- 15 N = 415 = 109 possible variants
- All amino acids at 5 positions - variantion is very high (109). Consider reducing the complexity of the library.
- Using 5xNNK would reduce the complexity to 3*107
Basic GeneStrands library - starting from €309*
Linear Libraries are PCR products harbouring a certain number of degenerated positions. During oligo synthesis degenerated positions are introduced.
Specifications
- Standard sequence up to 1000 bp
moderate GC content (35-75%), without extensive repeats (>25bp) or critical hairpin structures and without extensive homopolymer stretches (>18bp)
- Scale up to 500 ng
- Delivery format: lyophilised PCR product
Quality controls
- Single strand sequencing of the linear library
Incorporate wobble bases into GeneStrands - get a linear DNA library at very competitive prices
At Eurofins Genomics you pay per stretch of degenerated positions, not for every single position. This makes our linear libraries very attractive. Always keep in mind that complexity can increase quickly into astronomically high numbers. Therefore it is a good idea to keep complexity of your library as low as possible.
We also have mention one point: we cannot entirely exclude the possibility that, after cloning, you might find clones that harbour additional mutations elsewhere in the sequence. This is due to the nature of the gene synthesis process, where we use highest quality oligos; but even the best oligos do harbour mutations at very low frequencies (about 1 in 2000 bp). However, this might even result in serendipity, maybe you find the unexpected variant, that otherwise would not have been identified. Serendipity means "making discoveries by accident" or "pleasant surprise".
If you absolutely need 100% correct sequence outside the degenerated stretches, just contact us!. We will then discuss the project with you and offer a solution for your needs.
Ready-to-Use
A cloned library basically is a linear library that has been cloned into a plasmid.
We offer cloning into our Gene Synthesis standard vector pEX-A2 (map) or in a vector of your choice. We routinely deliver plasmid libraries at complexities of up to 108.
Specifications
- Standard sequence up to 1000 bp
moderate GC content (35-75%), without extensive repeats (>25bp) or critical hairpin structures and without extensive homopolymer stretches (>18bp)
- Diversity up to 108 variants per library
- Scale approx. 500 µg
- Delivery format: complete library in one tube
Quality controls
- Double strand sequencing of the cloned library
- Single strand sequencing of 10 single clones
QC criteria
100% sequence homology of the cloned library to the expected sequence, mixed peaks at degenerate positions. Please note that for some libraries due to the degenerate positions a higher-than-usual background elsewhere in the sequence can occur.
Additional options
- Sequencing of 96 individual plasmids
- Statistical data analysis (Chi2 value) of 96 clones, see graph on the top right
- Glycerol culture of the cloned library
Important information
We cannot entirely exclude the possibility that, after cloning, you might find clones that harbour additional mutations elsewhere in the sequence. This is due to the nature of the gene synthesis process, where we use highest quality oligos; but even the best oligos do harbour mutations at very low frequencies (about 1 in 2000 bp). However, this might even result in serendipity, maybe you find the unexpected variant, that otherwise would not have been identified. Serendipity means "making discoveries by accident" or "pleasant surprise".
If you absolutely need 100% correct sequence outside the degenerated stretches, just contact us!. We will then discuss the project with you and offer a solution for your needs.
Tip
If you add a promoter and a terminator to your library sequence, you can get an expression plasmid ready for high-throughput screening.
Libraries, Libraries, Libraries
In addition to the Combinatorial Libraries we also offer:
- (Ala) Scanning Libraries
Identify essential amino acids (aa) positions within an ORF (coding sequence
- Site Saturation (Mutagenesis) Libraries
Test all possible amino acids at one site (triplet / codon)
- Truncation Libraries
Shortened versions of a full-length gene
If you are interested in one of these libraries, just contact us!