Incubation advantages

The main advantage of using synaptosomes is that they are free from any influence of the parent axon. Another is that, since the volume of extracellular space (the incubation medium) is functionally infinite, transmitter will not accumulate near the synaptosomes. This means that reuptake of released transmitter is unlikely to occur and that, under drug-free conditions, transmitter release will not be modified by activation of auto- or heteroceptors (see below). 

In a study involving decalcified FFPE rat joint tissue sections and a variety of AR methods, Wilson et al.32 reported successful application of 0.2 M boric acid at pH 7.0 as the AR solution combining a low-temperature incubation (60°C for 17 h). The principal advantage of this AR protocol was that it minimized lifting or loss of decalcified hard tissue sections from charged slides. Their basic approach for establishing an optimal AR protocol was a test battery as described above. In a separate series of studies, based upon prior... 

Enzyme-linked immunosorbent assay (ELISA) is comparable to the immuno-radiometric assay except that an enzyme tag is attached to the antibody instead of a radioactive label. ELISAs have the advantage of nonradioactive materials and produce an end product that can be assessed with a spectrophotometer. The molecule of interest is bound to the enzyme-labeled antibody, and the excess antibody is removed for immunoradiometric assays. After excess antibody has been removed or the second antibody containing the enzyme has been added (two-site assay), the substrate and cofactors necessary are added in order to visualize and record enzyme activity. The level of molecule of interest present is directly related to the level of enzymatic activity. The sensitivity of the ELISAs can be enhanced by increasing the incubation time for producing substrate. 

Optophoresis has the advantage over other cell-based assays in that a small population of cells is used, and individual data on the drug response of each cell in the population is acquired. In this way subpopulations in a heterogeneous sample can be detected and analyzed. In addition, because of the low number of cells required, the cells do not need to be grown out or manipulated in any way. They are merely incubated with the drug ex vivo for the appropriate time to obtain a cellular response and then measured. 

The major advantage associated with continuous assays is that the initial rate of product formation can be determined with complete confidence, and any unusual behavior of the enzyme would be immediately apparent. The major disadvantage is a question of throughput an instrument such as a platereader would remain dedicated to the reading of a single plate for the duration of the enzyme-substrate incubation period, compared with an equivalent discontinuous assay where an entire plate may be measured in a... 

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