Assay, validity

Assay validation using incurred or fortified tissues... 

Assay conditions as determined by ASSAY VALIDATION are performed in the chosen PLATE FORMAT with an acceptable signal to background ratio as described by the Z factor. 

C. Kotts, E. Gilkerson, D. Trinh, G. Hawker, A. Chen, H. Gazzano-Santoro, Assay validation report Cell proliferation test for human growth hormone, Pharmacopeial Forum, 25(3), 8313 (1999). 

Compounds from traditional drug space ( common drugs —readily available from chemical suppliers), often chosen for studies by academic laboratories for assay validation and computational model-building purposes, can lead to misleading conclusions when the results of such models are applied to real discovery compounds, which most often have extremely low solubilities [16]. 

Gerberick, G.F. et al., Local lymph node assay Validation assessment for regulatory purposes, Am. J. Contact Derm., 11,3, 2000. 

The use of higher chromatographic flow rates has become an increasingly accepted technique to decrease the HPLC-MS cycle time during assay validation and bioanalysis. 

Genomic Testing and Data Quality Issues 11.4.1 Single-Nucleotide Polymorphisms Assay Validation... 

Assays Validated methods of analysis (e.g., ELISA for MAb), QPCR for residual DNA, and potency assays for vaccines... 

Direct isolation of sufficient quantities of each metabolite for structural characterization, assay validation and pharmacological or toxicological testing from in vivo studies using biological specimens is, therefore, often impossible, particularly from dmgs with a low therapeutic index. Furthermore, many metabolites have structural modifications which are difficult to replicate by traditional chemical methods. A number of synthetic steps may be required to prepare such metabolites from the API, or, in the worst case, a completely new synthetic route may need to be developed. 

The USP requirements for assay validation are very close to the ICH proposal. Here, three categories are distinguished. Category I corresponds to ICH assay, category II corresponds to ICH determinations of impurities. The additional category III includes analytical methods for the determination of performance characteristics (e.g., dissolution, drug release). For this category, the ICH assay characteristics are always sufficient. The objective of the analytical procedure... 

These five controls are representative of both assay validity and reproducibility. 

As noted earlier, there are several agencies or centers for alternative assay validation. Their processes are briefly summarized below. 

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