Biomedical applications sample preparation

Jakubowska, N., Polkowska, Z., Namiesnik, J., Przyjazny, A. Analytical applications of membrane extraction for biomedical and environmental liquid sample preparation. Crit. Rev. Anal. Chem. 35, 217-235 (2005)... 

This chapter provides a catch-all covering applications for which no or minimal sample preparation is required. More complex applications (forensic, biomedical and environmental) for which sample preparation are often a critical step are dealt with in Chapters 10 and 11. 

Scanning force microscopy (SFM) has been widely used for visualization of biomedical objects because of combination of extreme resolution, simplicity of sample preparation and ability to operate under physiological conditions. Nowadays SFM is increasingly applied to investigate the ultrastructure of biomedical samples embedded in epoxy resin [1]. In the present work, we are focusing on application of SFM, confocal laser scanning microscopy and ultramicrotomy to the K562 leukemic cells study. 

Ion-exclusion chromatography finds numerous applications for identification and determination of acidic species in complex matrix materials, such as dairy products, coffee, wine, beer, fruit juice, and other commercial products which can be quickly analyzed with minimal sample preparation before injection (usually only filtration, dilution, or centrifugation). Organic acid determination is also of great importance in biomedical research (e.g., physiological samples, in which most of the Krebs cycle acids (tricarboxylic acid cycle) are present). 

Liu et al. (2003) focused their method paper on the instrumental set-up for on-line capillary LC coupled with MS-MS via a low flow-rate interface, hoping that miniaturization would improve sensitivity for many biomedical applications. The system design and perfonnance were tested on DHEA sulfate and pregnenolone sulfate quantitation from 5 pL of plasma from one male volunteer. Sample preparation was simple - addition of aqueous methanol and of the deuterated analog internal standards, protein precipitation, supernatant filtration through a Cig bed, evaporation and reconstitution in 100 pL of mobile phase, of which 20 pL were injected for LC-MS-MS analysis. The DHEA sulfate concentration found was in agreement with literature values based on GC-MS and LC-MS studies. 

AMS does not determine the absolute concentration of isotopes rather an isotope ratio of a rare isotope to an abundant stable isotope of the same element is measured. There is no commercially available AMS instrument that measures all isotopes, such that most instruments are built to detect one or two elements only. Highly specialized, complex, and time-consuming sample preparation is often required prior to AMS analysis. AMS instruments for various radioisotope analyses have been reviewed in a recent publication [14], Here we would only discuss AMS instrument for 14C analysis, the most important radioisotope for biomedical applications. For 14C measurement, an AMS instrument usually consists of an ion source to generate negative ions, a low magnetic field for initial ion separation, a high-voltage... 

Various kinds of colloidal particles have been used in biomedical domains. In analytical chemistry, they are used as sohd supports for sample preparation. In the drug dehvery field, nanocolloids, and particularly stimuli responsive polymer-based nanogels, have been intensively explored as protein carriers for in vivo applications. The reported smdies in this direction are mainly focused on the release efficiency rather than on the driven forces involved in the loading and the release of the loaded proteins. 

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