Oligo , direct

We order our DNA oligos using a small scale (10 or 50 nmol) and have them desalted. We have the oligos shipped in liquid form at 100 pM. This allows us to use 1 pL of the oligo directly in a 100 pL PCR amplification. 

Biosynthesis of the polypeptide chain is realised by a complicated process called translation. The basic polypeptide chain is subsequently chemically modified by the so-called posttranslational modifications. During this sequence of events the peptide chain can be cleaved by directed proteolysis, some of the amino acids can be covalently modified (hydroxylated, dehydrogenated, amidated, etc.) or different so-called prosthetic groups such as haem (haemoproteins), phosphate residues (phosphoproteins), metal ions (metal-loproteins) or (oligo)saccharide chains (glycoproteins) can be attached to the molecule by covalent bonds. Naturally, one protein molecule can be modified by more means. 

Even if the main focus on the research activities were directed towards structural studies on carbohydrates of natural origin, the synthesis of model substances, deriva-tization of oligo- and poly-saccharides, oxidation, and reduction of carbohydrates, and identification of the products all were performed during this time. 

It has been reported that the electrical properties of single molecules incorporating redox groups (e.g. viologens [114, 119, 120, 123, 124], oligophenylene ethynylenes [122, 123], porphyrins [111, 126], oligo-anilines and thiophenes [116, 127], metal transition complexes [118,128-132], carotenes [133], ferrocenes [134,135],perylene tetracarboxylic bisimide [93, 136, 137] and redox-active proteins [138-143]), can be switched electrochemically. Such experiments, typically performed by STM on redox-active molecules tethered via Au-S bonds between a gold substrate and a tip under potential control, allow the possibility to examine directly the correlation between redox state and the conductance of individual molecules. 

Oligo administration during many clinical trials entails direct i.v. infusion, often over a course of several hours. S.c. and, in particular, intradermal administration is usually also associated with high bioavailability. 

Especially noteworthy are the methods for determining the sequence of glycosyl residues in a complex oligo- or poly-saccharide. Methods of this type generate a series of overlapping oligomers that are separated and identified by l.c., in conjunction with either direct or indirect mass spectrometry. Most of these methods are still in the developmental stages, and they often require expensive and not-routinely available equipment (see also. Section IV,2) (see Addendum). 

The only example known for the formation of azetidine 82 by direct intramolecular aza-Wittig reaction is the reaction of the /3-azidoketone 81 with triphenylphosphane (Scheme 41). Attempts to transfer this reaction to 83 and 84 were not successful (87NKK1250). This failure can be attributed to the formation of intermediates with highly energetic transition states, where the rate of intramolecular attack on the carbonyl function is so slow that oligo- and polymeric compounds are preferentially formed. 

Hamaguchi, Y, Aso, Y, Shimada, H., and Mitsuhashi, M., Direct reverse transcrip-tion-PGR on oligo(dT)-immobilized polypropylene microplates after capturing total mRNA from crude cell lysates, Clin. Chem., 44, 2256-2263, 1998. 

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