Nephelometry applications

Currently available solubility models based on turbidimetry as well as nephelometry are not very predictive and are limited in their broad applicability, because they make use of training data from different laboratories determined under varying experimental conditions [130]. However, the access to many aqueous solubilities measured under standardized conditions is expected to greatly improve currently available models. 

Green C, McKee S, Saunders K A fully automated Kinetic solubility screen in 384-well Plate format usinig nephelometry. BMG, Application Note 117... 

Light scattering is a physical phenomenon resulting from the interaction of light with particles in solution. Nephelometry and turbidimetry are analytical techniques used to measure scattered light. Light-scattering measurements have been applied to immunoassays of specific proteins and haptens. Specific applications are described in Chapters 9,20, and 26. 

The choice between turbidimetry and nephelometry depends on the application and the available instrumentation. Neph-eloraetry, however, sfill offers some advantage in sensitivity when measuring low-level antigen-antibody reactions. ... 

These two optical techniques are particularly applicable to methods measuring the precipitate formation in antigen antibody reactions (see Chapter 9). Turbidimetry is used in several chemistry immunoassay systems for therapeutic drug monitoring and specific protein assays. Details of turbidimetry and nephelometry are discussed in Chapter 3. 

The applications of automatic continuous segmented analysers can aiso be classified according to the type of detection system involved. Thus, 70-75 of all the methodologies described on this topic used molecular UV absorption spectroscopy (spectrophotometry, photometry), followed by ISE potentiometry (10-15 ) and, much less often, nephelometry, fluorimetry, etc. The applications described below were mostly developed with the aid of Technicon technology and are classified according to this criterion —other applications to specific problems related to laboratory processes are described in the corresponding chapters. 

Chemical imaging is described, including confocal Raman imaging. UV and visible spectroscopy includes innovations such as flow-through sample holders and fiber-optic probes, as well as instruments for analysis of submicroliter volumes and nondestructive analysis for nucleic acid and protein determinations. UV absorption spectral interpretation for organic molecules is covered in depth. Applications described include nucleic acid and protein measurements, spectrophotometric titrations, and new applications in forensic chemistry. Nephelometry, turbidimetry, fluorescence, and phosphorescence are described in detail, including instrumentation and applications. The measurement of color using the CIE system is described with examples. 

Antibodies have been used in analysis for over 60 years, and offer an unexpectedly wide range of techniques and applications. In some cases, the specific combination of an antibody with the corresponding antigen or hapten can be detected directly (e.g., by nephelometry), but more often such reactions are monitored by a characteristic label such as a radioisotope, fluorophore, etc. Since antibody reactions do not have a built-in amplification effect, these labels are frequently necessary to provide sufficient analytical sensitivity. Antibodies of different classes vary greatly in stability, but some are relatively robust proteins, and this contributes significantly to the range of methods available. 

Strzelak, K. and R. Koncki. 2013. Nephelometry and turbidimetry with paired emitter detector diodes and their application for determination of total urinary protein. Anal. Chim. Acta 788 68-73. 

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