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Here are some more information for Capillary Electrophoresis:

Different Method To Purify Synthetic Oligonucleotides

Since the pioneering work of Letsinger and Lunsford to today’s applications in synthetic biology, where one can synthesize entire chromosomes( by PCR /overlapping oligos methodologies) there are a number of purification methods including but not limited to;

1. RP-HPLC. One uses the Trityl on strategy, where the trityl group is left after the last addition cycle, this provides enough hydrophobicity to be retained in a C-18 column, and separation is possible. This works up to fragments of about 30-35 nucelotides in length, after that , the overall hydrophobicity of the oligos does not allow separation

2. Variations of RH-HPLC, this include the so called cartridge based purifications; using trityl on, one uses small 1-2 cm in length so called Sep-Paks(Waters Corp) to purify; generally this renders purities of 80-90 %, and again limited to 30-35 mers

3. Capillary Electrophoresis (CE). Unless one can collect the eluates and very small amounts of oligo are needed, this is not truly a purification method, rather a QC method to check purity.

4. Ion-exhange HPLC. This method can purify with better resolution, in some cases, than RP-HPLC; makes use of ion-pairing agents. The drawback here is the potential for HPLC damage if leftover salts are left in the HPLC system

5. Polyacrylamide Gel Electrophoresis (PAGE). This is perhaps

6. The oldest method, less automated one (does not require expensive equipment) and after all these years in our opinion, remains perhaps the best purification method for oligonucleotides, due to the exquisite single base resolution properties. The drawback is that one has to manually prepare the GEL (10-20%) and works well to purify oligos in the range of 50-100 OD’s.

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Advantages and disadvantages of electrophoresis?

Can you list at least 2 advantages and 2 disadvantages of capillary and gel electrophoresis? 10 points will be awarded for best answer.

Advantages of Gel electrophoresis:
Cheap. It doesn't cost much to obtain agarose or poly-acrylamide

Quick. Depending on what you're looking, it could take an hour to get your results. Unless you're doing blots, which take a little longer, perhaps a day or two, depending.

Disadvangtages:
Toxicity. DNA visualization uses dyes like Ethidium Bromide which chelate DNA and is a known carcinogen. Although some safer alternatives are becoming available (SYBR Safe). Polyacrylamide, used as a matrix in protein gels is also a known neurotoxin.

Accuracy. Unless you're going to use densitometry to measure the density of each protein or DNA band, Gels can't really give you an accurate idea of the concentration or abundancy of your protein or DNA.

Studying the Individual Cell
A cell is just one individual in a population, perhaps making up a tissue or part of a bacterial colony living in the human gut or in the ocean.

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