Nucleic Acid Columns

Ion Exchange Chromatography

The separation of synthetic oligonucleotides of defined length and sequence, and the separation of DNA restriction fragments are required for modern genetic engineering and in molecular biology. The ion exchange columns, HYDROCELL NS 1500 was developed specifically for the purification of PCR products, short nucleic acids from two to forty or more nucleotide residues and DNA restriction fragments of up to 1000 base pairs. NS 1500 is produced from 10 µm of highly cross-linked PS-DVB beads with pore diameter of 500 Å.

pBR322 and pUC18 / Hae III digest DNA markers were used as model samples of DNA restriction fragments. At room temperature, these fragments were efficiently resolved on a HYDROCELL nucleic acid column.

pBR322 Hae III digest on DEAE NP10 column

pBR322 Hae III digest on NS 1500 column

pUC18 Hae III digest on DEAE NP10 column

pUC18 Hae III digest on NS 1500 column

Excellent separation was obtained in 15 minutes when the oligonucleotide standard, oligothymidylic acid d(pT) 12-18 mer, was chromatographed using the nucleic acid column. The larger oligonucleotide fragments can be purified by adjustment of elution conditions. They require higher concentrations of salt and longer times for elution.

In addition to their use in process monitoring and quality control analysis of proteins and enzymes, Non-Porous Anion Exchangers, DEAE NP10 and QA NP10 high-speed columns are also suitable for the analysis of small nucleotides, oligonucleotides, and DNA fragments.  High loading capacity and low back pressure are the unique characteristics of these columns.  These characteristics allow the easy scale-up from analytical to preparative separations.  The sensitivity of non-porous anion exchangers is better and retention time is shorter than NS 1500.  It is recommended for the trace analysis and rapid scanning of complex samples.

Oligonucleotides on QA NP10 column

Oligonucleotides on NS 1500 column

Ion-Pair Reversed Phase Chromatography

Denaturing HPLC (DHPLC) is an ion-pair reversed phase high performance liquid chromatography (IP-RP-HPLC) at temperature 35° to 80°C. It can be used for DNA fragment analysis, PCR quantification and cleanup before sequencing or cloning. DHPLC can identify variation by detecting heteroduplex formation between reannealed wild-type and mutant PCR fragments. It is a method of the detection of mutation and genomic variation that is amenable to a sequencing core environment.

pUC18 Hae III digest on NRD 2 Column

21-Mer 5'DMT Oligonucleotide on RP 20S Column
 

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                          Carbon Nanotubes sorting and purifying
                      by Ion Exchange Chromatography

Wrapping of carbon tubes by synthetic single-stranded DNA was found that electrostatics of the DNA-CNT hybrid depends on tube diameter and electronic  properties, enabling nanotube separation by anion exchange chromatography. Optical absorption and Raman spectroscopy show that early fractions are enriched in the small diameter and metallic tubes, where late fractions are enriched in the large diameter and semiconducting tubes.  The purification of semiconducting single- walled carbon nanotubes (SWCNT) with a purity of 99% or higher is important in the electronic industry. The purification of semiconducting SWCNT from metallic SWCNT are related to hydrophilic and ligand density of anion exchange packing materials,  column dimension  and DNA-CNT hybrid.

The following are the comparison of conventional NS 1500 column to  CNT-NS 1500 column in the separation of single stranded synthetic oligonucleotides standard mixture. Hydrocell CNT-NS 1500 showed the longer and wider retention time in the separation of the same standard sample of 12-18 mer of phosphated oligothymidylic acid in the comparison with conventional NS 1500 for oligonucleotides and DNA fragment purification..  The relationship of DNA-CNT hybrid and the characteristic of  anion exchange packing materials in the purify semiconducting single-walled carbon nanotubes are under investigation.

     Conventional Hydrocell NS 1500  Column                  Hydrocell CNT-NS 1500 Column