Beads coating

When the bacteria to be detected are less than 1% of the total population in a sample, IFAs cannot be used because of interference from unrelated particles that are concentrated when large volumes of sample are filtered. To overcome this problem, the organism of interest may be concentrated by immunomagnetic separation.10,51 62 For this procedure magnetic beads coated with monoclonal or polyclonal antibodies are mixed with the sample. The beads are collected with a magnet, and the cells attached to the beads then are removed, enumerated, and identified by IFAs. 

Figure 8.1 The results of IHC of two experiments using Dynabeads (Dynal, New York, NY) coated with biotinylated anti-mouse IgG (first experiment) and protein S-100 (second experiment), (a) Positive control showing red color (S-100) localized in the melanoma cells, (b) Strong positive red color circles all beads coated with biotinylated anti-mouse antibody after the heating AR treatment (first experiment), (c) Using the heating AR treatment, S-100-coated polymer beads show positive red color around the beads as circles (second experiment), (d) Negative control of the first experiment. No red color could be seen for polymer beads (arrows) that had been treated with exactly the same protocol as that of slide (b), but omitting the avidin-biotin-peroxidase (label). Bar = 50pm. Reproduced with permission from Shi et al., J. Histochem. Cytochem. 2005 53 1167-1170. See color insert.

Fig. 4.3 SEM images of the long range packing assembly of composite colloidal crystal array films assembled on different substrates (a) polycarbonate sheet, (b) Teflon sheet, and (c) Teflon film. The submicron particles were composed of 326 nm diameter polystyrene beads coated with a 20 nm thick Si02 shell. Scale bars in (a c) are 3.00, 3.00, and 2.72 pm, respectively...

Parallel Synthesis We start the reaction by using two sets of building blocks, amines (A) and carboxylic acids (B). The amines are first attached to solid supports, normally polystyrene beads coated with linking groups, in separate reaction vessels for each amine. After the amines have been attached, excess unreacted amines are washed off. Next, the carboxylic acids are added to the amines to form the desired amides. We illustrate these steps in Fig. 3.8. Assuming there are 8 amines to react with 12 carboxylic acids in a 96-well plate with 8 rows and 12 columns of tiny wells, the amines, A1 to A8, are added across the rows to each well containing the polystyrene beads. Different types of carboxylic acids, B1 to B12, are added to the wells in each column. 

Studies have been made to find an alternative to RPC-5 because it is no longer commercially available. Homemade RPC-5 or Kel-F beads coated with Adogen 464 as the stationary phase manifested resolution and elution order comparable to that obtained on RPC-5 under similar conditions (440). Recently, Usher (443) has shown that DNA restriction fragments, oligonucleotides, and tRNA can be fractionated by using only Kel-F powder without Adogen as the stationary phase. The mobile phase... 

Preparation of cells for use with either immunomagnetic beads preconjugated with MAbs or immunomagnetic beads coated with antimouse IgG antibodies... 

Detachabead is available from Dynal for positive selection of CD4+, CD8+, CD 19+, and CD34+ cell subsets (23-30) This reagent has also been used to select positively for CD45+ cells (31), HLA-DR+ Langerhans cells (32), and c-kit+ human lung mast cells (33) However, its suitability for dissociation of beads coated with MAbs of other specificities should always be assessed by the user in a pilot study. 

Hansen, T. and Hannestad, K. (1989) Direct HLA typing by rosetting with immunomagnetic beads coated with specific antibodies. J. Immunogenet. 16,137—139. 

Widjojoatmodjo, M. N., Fluit, A. C, Torensma, R, and Verhoef, J (1993) Comparison of immunomagnetic beads coated with protein A, protein G, or goat antimouse immunoglobulins. J. Immunol Methods 165, 11-19... 

R. O. Williams III and J. Liu. Influence of processing and curing conditions on beads coated with an aqueous dispersion of cellulose acetate phthalate. Eur. J. Pharm. Biopharm. 49 243-252, 2000. 

Iskakov, R. M., Kikuchi, A., and Okano, T. Time-programmed pulsatile release of dextran from calcium-alginate gel beads coated with carboxy-re-propylacrylamide copolymers. J. Contr. Rel. 80 57-68, 2002. 

Capillary electrophoresis subsequent to immunosubtraction, which entails incubating the serum sample with beads coated with specific antisera followed by analysis of supernatants, is an attractive alternative to immunofixation and is amenable to automation (K36). 

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