Screen analyses differential

Reliable and internationally accepted techniques for screening are differential scanning calorimetry (DSC) and differential thermal analysis (DTA). These techniques can provide exothermic enthalpy of reaction and observed... 

Whether strong control of FWER or FDR is appropriate in the analysis of microarrays may depend on how the inference on differential gene expressions is used subsequently. In one form of drug discovery, genes are first screened for differential expressions under normal and disease conditions. Subsequently, nucleotide sequences in the promoter regions of the genes selected in the first step are mined for unusually common sequences (called consensus motifs). Proteins (transcription factors) that bind to these motifs then become candidates for drug compounds to intervene with the disease process. 

The isolation of the benzolactone enamide salicylihalamide A 17101 (Scheme 6.1 Part 2) was guided by the NCI s Drug Discovery Research and Development, Developmental Therapeutics Program screen for differential cytotoxicity, which showed that the Australian sample of Haliclona possessed a unique 60 cell line profile. Nanomolar potency was evident in the melanoma cell lines (GI50 = 7 nM) and a COMPARE analysis of the 60 cell line data indicated vascular ATPase (V-ATPase) activity potential. Further study of this structure class determined that salicylihalamide A is equipotent to the V-ATPase standards bafilomycin A and concanamycin A,273 but unlike these standards, selectively inhibits mammalian V-ATPases. 

Many research projects that aim to establish the identity of differentially expressed genes from two or more samples would not necessarily benefit from the microarray approach compared to more conventional methods such as subtractive library screening or differential display. Initial considerations as to the suitability of this technique to a particular application include whether more than two samples are being compared, how many differences might be expected, and what proportion of the total number of transcripts from the target tissue are known or have been cloned. In addition, the practical issues of availability of array robotics and analysis hardware and technical expertise must all be considered. 

ARC = Accelerating Rate Calorimeter (Columbia Scientific Instrument Corp.) DSC = Differential Scanning Calorimeter DTA = Differential Thermal Analysis RC1 = Reactor Calorimeter (Mettler-Toledo Inc.) RSST = Reactive System Screening Tool (Fauske and Associates) VSP = Vent Size Package (Fauske and Associates) ... 

Differential Thermal Analysis (DTA) A sample and inert reference material are heated at a controlled rate in a single heating block. This test is basically qualitative and can be used for identifying exothermic reactions. Like the DSC, it is also a screening test. Reported temperatures are not reliable enough to be able to make quantitative conclusions. If an exothermic reaction is observed, it is advisable to conduct tests in the ARC. 

Differential thermal analysis (DTA) Chemical testing technique that produces similar data to DSC. DTA uses temperature differences to generate test results DSC has largely replaced the DTA technique as a screening tool for obtaining chemical hazard test data... 

To K. 2000. Identification of differential gene expression by high throughput analysis. Comb Chem High Throughput Screen 3 235. 

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