• All DNA oligonucleotides provided by ABT are chemically synthesized, not enzymatically. Therefore, there is no DNase or RNase in the products.

  However, customers should be aware that various nucleases are present in most environments, so good laboratory practices are crucial to minimize the risk of contamination.

The oligonucleotides provided by ABT undergo a standard salt deprotection step. Initially, no inorganic salts, such as sodium or magnesium, are used during the chemical synthesis of DNA. Our standard salt deprotection step refers to the removal of small organic molecules remaining after the synthesis process. For example, acrylonitrile produced from the deprotection of the main phosphodiester backbone is a residual by-product from the cleavage and deprotection process. For many techniques/applications, including PCR, salt deprotection may be acceptable for oligonucleotide bases smaller than 35 bases. Longer oligonucleotides may require additional purification, such as Cartridge. The salt deprotection process will eliminate the majority of these organic molecules, although a very small amount may still exist in a shipped oligo.

• To ensure long-term storage of oligos, temperature is the most critical factor to consider. For extended storage, whether the oligo is dried or in liquid form and untreated with DEPC or stored in TE buffer (10 mM Tris pH 8.0, 0.1 mM EDTA), it is recommended to store oligos at -20°C.

  When stored under these conditions, oligos remain stable for at least 60 weeks, whether stored in dried form or rehydrated in water or DEPC-untreated TE buffer (10 mM Tris pH 8.0, 0.1 mM EDTA).

  It is important to note that for DNA oligos, acidic pH can lead to purine reduction, so maintaining a neutral pH is crucial.

The optimal concentration commonly used for primers in PCR reactions is 500 nM for each primer in the reaction.

• The minimum length of custom DNA oligos that ABT can synthesize is 6 bases. For a detailed list of length restrictions for our custom DNA Oligos, please visit our DNA Oligos catalog page.
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• ABT is open to reviewing requests for shorter oligos. If interested, please contact us and provide details about the sequence, scale, purity requirements, etc., and we will assess your request. Please note that the review process may take some time.

Standard desalted oligos can be used in common DNA applications such as PCR, qPCR, and DNA sequencing.

When receiving oligo products in dry form, the oligo can be reconstituted in TE buffer (10 mM Tris pH 8.0, 0.1 mM EDTA) or molecular biology-grade water.

We synthesize oligos in the 3′ ─> 5′ direction on CPG beads using amidite chemical synthesis.

The purification process eliminates shortmers (short sequences) and other synthetic impurities. Our experience indicates that purifying oligonucleotides for applications requiring high purity will save both time and costs in the long run. We recommend considering additional purification for any oligonucleotide intended for an application beyond conventional PCR, qPCR, or Sanger DNA sequencing.