Colloids labelled

If the excess of lanthanide is sufficiently great, overloading of the transport system occurs and colloidal aggregates of large size are formed by hydrolysis. The interstitial or intracavitary formation of immobilized lanthanide colloids labeled with relatively short-lived radioisotopes was the basis for the attempted use of radioactive lanthanides as internal sources of therapeutic radiation (Kyker, 1962a, 1962b). 

Chen, H., Jiang, J. H., Huang, Y., Deng, T., Li, J. S., Shen, G. L., and Yu, R Q. (2006) An electrochemical impedance immunosensor with signal amplification based on Au-colloid labeled antibody complex. Sens. Actuators B 117,211-218... 

The behavior of stannous ion in kit preparations has been studied in a limited number of compounds, and the conclusion reached so far indicates that, apparently, tin ions only reduce TcOj and indeed, apart from some tin-essential preparations such as stannous oxide colloid labeled with " Tc (Subramanian and McAfee 1970), mixed Tc-Sn complexes have not been observed in low-molecular-weight radiopharmaceutical preparations. 

Subramanian G, McAfee JG (1970) Stannous oxide colloid labeled with ""Tc or " In for bone marrow imaging. J Nucl Med 11 365-366... 

Observation of the electrode under examination being exposed to an electric field may yield information about the value of E. Any charge on the electrode, which can be a wire or a colloidal particle, will result in a movement in the external field. Assuming that the movement is due to charges being present on the electrode the rate of the movement should pass through a minimum at E i.c provided that specific adsorption is absent. (Data obtained with this method are labelled ED). 

FIG. 9 Confocal laser scanning micrograph of a hollow polymer capsule. The polymer capsule was obtained from polymer multilayer-templated FDA microcrystals after removal of the colloidal core. The FDA microcrystals were coated with SDS and 11 polyelectrolyte layers [(PAH/PSS)3/PAH/ (PSS/PAH-FITC)2]. (PAH-FITC = PAH labeled with fluorescein isothiocyanate.) The microcrystal core was removed by exposure of the coated microcrystals to ethanol, causing solubilization of FDA. 

An important development has been the isolation of bacteria that were able to degrade phenan-threne that was sorbed to humic acid material (Vacca et al 2005). Enrichment was carried ont with PAH-contaminated soils using phenanthrene sorbed to commercial hnmic acid. Only the strains isolated from this enrichment were able to carry ont degradation of C-labeled phenanthrene, and this exceeded by factors of 4-9 the amonnt estimated to be available from the aqneons phase alone. It was snggested that specially adapted bacteria might interact specifically with natnrally occnrring colloidal material. 

Wen LS, Santschi PH, Tang DG (1997) Interactions between radioactively labeled colloids and natural particles Evidence for colloidal pumping. Geochim Cosmochim Acta 61 2867-2878 Whitehouse BG, Yeats PA, Strain PM (1990) Cross-flow filtration of colloids from aquatic environments. Limnol Oceanogr 35 1368-1375... 

The typical viscous behavior for many non-Newtonian fluids (e.g., polymeric fluids, flocculated suspensions, colloids, foams, gels) is illustrated by the curves labeled structural in Figs. 3-5 and 3-6. These fluids exhibit Newtonian behavior at very low and very high shear rates, with shear thinning or pseudoplastic behavior at intermediate shear rates. In some materials this can be attributed to a reversible structure or network that forms in the rest or equilibrium state. When the material is sheared, the structure breaks down, resulting in a shear-dependent (shear thinning) behavior. Some real examples of this type of behavior are shown in Fig. 3-7. These show that structural viscosity behavior is exhibited by fluids as diverse as polymer solutions, blood, latex emulsions, and mud (sediment). Equations (i.e., models) that represent this type of behavior are described below. 

Ni J., Lipert R.J., Dawson G.B., Porter M.D., Immunoassay readout method using extrinsic Raman labels adsorbed on immunogold colloids, Anal. Chem. 1999 71 4903-4908. 

One particularly novel carrier was reported to consist of 50-70 nm colloidal gold particles of the type often used in cytochemical labeling techniques for microscopy (Pow and Crook, 1993) (Chapter 24). Adsorption of peptide antigens onto gold and subsequent injection of the complex into rabbits in an adjuvant mixture resulted in rapid production of antibody of extremely high titer. The resultant antibodies could be used in immunocytochemistry at dilutions from l-in-250,000 down to l-in-1,000,000, which is orders-of-magnitude beyond the dilutions typically used with lower-titer antibodies. 

Colloidal gold-labeled (strept)avidin can be used as highly sensitive detection reagents for microscopy techniques (Cubie and Norval, 1989) (Chapter 24). Finally, cytotoxic substances coupled to (strept)avidin can be used to direct cell-killing activity toward a tumor-cell-bound, biotinylated monoclonal antibody (or other targeting molecule) for cancer therapy (Hashimoto et al, 1984) (Chapter 21). 

The following sections discuss the preparation of colloidal gold suspensions of various particle sizes and their use in labeling proteins for detection purposes. Gold-labeled molecules and proteins are available from a number of manufacturers (Janssen, E-Y Labs, and Nanoprobes). 

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