| 1. |
- Haupt, Dan, et al.
(författare)
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Separation of (R)- and (S)-naproxen using micellar chromatography and an alpha 1-acid-glycoprotein column : application for chiral monitoring in human liver microsomes by coupled-column chromatography
- 1992
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Ingår i: Journal of Biochemical and Biophysical Methods. - 0165-022X .- 1872-857X. ; 25:4, s. 273-284
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Tidskriftsartikel (refereegranskat)abstract
- A column-switching system for fast determination of (R)- and (S)-naproxen in liver microsomes has been developed. The centrifuged sample was injected directly onto a pre-column with octadecylcoated silica. The retained analytes were then directed to an alpha 1-AGP column using a mobile phase composed of phosphate buffer (pH 6.5), dimethylocytylamine (30 mM) and the nonionic surfactant, Tween 20 (40 g/l). The method gave high absolute recoveries and good repeatabilities: 99.6% (1.7% relative standard deviation) and 94.9% (2.4% R.S.D.) for the (R)- and (S)-naproxen, respectively. The use of a surfactant in combination with an aliphatic amine in the mobile phase involves reduced retention times with retained enantioselectivity. Furthermore, the presence of the surfactant makes it possible to inject biological samples directly into the chromatographic system.
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| 2. |
- Lammi, Mikko, 1961-, et al.
(författare)
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Autoradiographic quantitation of radiolabeled proteoglycans.
- 1991
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Ingår i: Journal of Biochemical and Biophysical Methods. - 0165-022X .- 1872-857X. ; 22:4, s. 301-310
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Tidskriftsartikel (refereegranskat)abstract
- Radiolabeled proteoglycans or glycosaminoglycans were precipitated with the cationic dye safranin O onto a sheet of nitrocellulose filter using a dot-blot apparatus. An autoradiography film was exposed against the nitrocellulose sheet. The developed film and the nitrocellulose sheet were separately digitized in a flat-bed-gray-scale scanner connected to a microcomputer. An image analysis program of the microcomputer was used to quantify the density of the radioactivity dots produced in the film, and the intensity of the dye spots on nitrocellulose. With this procedure, a single sample containing the minimum of about 20 ng uronic acid and 5 dpm of incorporated 35SO4 was quantified for both total glycosaminoglycan content and radioactivity. Unincorporated 35SO4 and low molecular mass radioactivity (e.g. products of glycosaminoglycan degrading enzymes) did not interfere since they were quantitatively washed through the membrane before the assay.
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| 3. |
- Thorén, Sven A., et al.
(författare)
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A microcalorimetric vessel for monitoring cytotoxic reactions in the micro-submicrowatt region
- 1990
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Ingår i: Journal of Biochemical and Biophysical Methods. - 0165-022X. ; 20:3, s. 217-225
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Tidskriftsartikel (refereegranskat)abstract
- A microcalorimetric vessel for monitoring the initial phases of cytotoxic reactions in the micro-submicrowatt region has been designed and tested. The vessel is intended to be used witha multichannel microcalorimetric system from Thermometric, Järfälla, Sweden and can be built up stepwise in a modular way. The different functions of perfusion, stirring and addition of small amounts of soluble immune reactants can be used separately but also in combination. This is accomplished by the use of a vertical stirring mechanism and a reaction vessel of low volume, 200 μl. The simplcity of the vessel permits an identical vessel to be used on the reference side, handled in parallel with the measuring vessel. No gas phase is present.
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