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Supported by Sangon Biotech
- One of the World Largest and the Most Experienced Suppliers
- Wide Range Product Lines
- All Oligos Passed QC by Mass Spectrometry Analysis
- Highest Purity at Lowest Price
- Specializing in HAP & PAGE Purification
- Fast Services: Completed within 24 / 36 Hours (for HAP or PAGE)
- All oligos with modified base are purified by HPLC (WAVE system)
Competitive Price – As low as 1.3HKD/bp
Over 100 modifications available
Quick & efficient shipping
Simple and automatic Quote & order, in a few minutes.
Frequently Asked Questions and Answers
Q: What’s the storage condition of oligonucleotide ?
Synthesized oligonucleotides are provided in lyophilized powder. Oligonucleotides in the form of lyophilized powder are relatively stable, it can be transported at ambient temperature and stored at room temperature for a couple of days. Oligos in lyophilized powder is stable for years when stored at -20℃. After reception, oligonucleotides are recommended to be dissolved in TE buffer to 100 ?M and stored at -20℃. It is stable for several months and freeze-thraw cycles should be avoided. A work solution in 10 ?M is always stable for several days if stored at 2-8℃.
Q: How do I measure the amount of oligonucleotides ?
An OD reading is a quick way of estimating how much DNA is contained in the solution, by measuring the absorbance at 260 nm. 1 OD is approximately 33 ?g of crude oligo DNA. It should be noted that, for especially desalted oligos, the OD reading is a measurement of the total amount of nucleic acid which includes both the full-length and failed sequences.
Q: What is HAP purification and how do I choose it ?
High Affinity Purification (HAP) is a patented, novel purification method for custom oligos developed by Sangon Biotech. DMT-ON-Oligo in the crude oligo mixture is first selectively absorbed on a high affinity resin in HAP column while incomplete oligos pass through. Final products is obtained by removing the protection group of DMT under mild acidic conditions. HAP method provides two major advantages, high purity superior to De-Salted method (>98%), and low cost compare to PAGE or HPLC methods. Oligos produced by the HAP method has such high purity that they can be directly used for any downstream experiments such as PCR, DNA Sequencing, Gene Synthesis, and Mutagenesis. At present, the most economic method to produce oligos is the De-Salted method, which however, yields products poor in purity. For example, the purity of 20-mer, 40-mer and 60-mer is approximately 68%, 45% and 30% respectively. This is calculated based on the 4 steps in DNA synthesis: De-DMT, Coupling, Oxidation and Capping. The average yield of each cycle is about 98%. The purity of 20-mer is therefore (0.98)20-1 = 68%; of 40-mer = (0.98)40-1 = 45%; and of 60-mer = (0.98)60-1 = 30%. Most laboratories use De-Salted oligos despite of their inferior purity because higher quality oligos produced by alternative methods such as PAGE, HPLC, and OPC are too costly. HAP presents the perfect alternative for high purity oligos at lowest prices. In fact, price is even lower than those of De-Salted method in some cases.
Q: What are the various purification options ?
During the synthesis of oligonucleotides, the crude products contain undesired oligos caused by side reaction as well as full-length oligos. Purification procedures are required to remove these undesired products and/or other component such as salts. Sangon Biotech offer 3 kinds of purification options for oligonucleotides.
HAP (High Affinity Purification): As described above.
PAGE polyacrylamide gel electrophoresis): Oligos purified by (PAGE) are run on a gel and the full-length product is excised and recovered by electroelution. Resolution of 1 base differences are possible. PAGE pure oligos are generally 96 to 99% pure.
Reverse Phase HPLC: This method also uses the 5′ trityl protecting group as a means of binding to the column. This method works well for oligos up to 55 bases and generally 90 to 95% pure.
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