Posters

By multiplexing a reporter assay (EnduRen™, ViviRen™) with a cell viability assay (CellTiter-Glo®), it is possible to determine if reporter response variations are due to changes in cell number and health. In this poster, we demonstrate the combination of several Promega cell-based assays multiplexed in both low-volume 384- and 1536-well plate formats using the BMG LABTECH PHERAstar microplate reader to record luminescence.

Cryopreserved hepatocytes express both phase I and phase II enzymes and facilitate early evaluation of the metabolic stability of pharmaceuticals. Availability of pre-pooled cryopreserved hepatocytes further enhances the utility of this model by reducing donor to donor variability. In this study, the metabolic stability of 29 pharmaceutical compounds were evaluated in pre-pooled cryopreserved human hepatocytes.

DB289 is a prodrug that is converted by several steps to the active metabolite DB75. DB289 exhibits enhanced oral efficacy and reduced acute toxicity over DB75, an aromatic dicationic compound that is effective against a broad range of pathogens in vitro including African trypanosomiasis (African sleeping sickness). This reaction phenotyping study aimed to identify the enzymes responsible for oxidative O-demethylation; the first step in this conversion to DB75.

The expression of CYP enzymes is influenced by both endogenous and exogenous factors. The aim of this analysis was to evaluate whether the age, gender, or ethnicity of the donor should influence the selection of human liver microsomes for drug metabolism studies, as well as whether cigarette smoking and alcohol consumption are reliable indicators of elevated CYP1A2 and CYP2E1 activity, respectively.

Alfentanil is a synthetic analgesic cleared exclusively by hepatic metabolism. Due to the highly linear correlation between alfentanil systemic clearance and CYP3A4 activity, as well as the direct pharmacologic effects on pupil size, it has been used as a non-invasive metabolic probe for CYP3A4 activity in vivo. AMX is a direct metabolite of alfentanil, evaluated in this study for its potential to measure CYP3A4 activity in vitro.

Marker substrates for certain CYPs have changed for several reasons, including the need for improved selectivity and sensitivity, reliable substrates for LC/MS/MS analysis, and substrates that provide greater repeatability. The objectives of this study were to compare sample-to-sample variation in cytochrome P450 enzymatic rates between two or more CYP-specific substrates and to determine Michaelis-Menten kinetic constants for these same reactions using a pool of human liver microsomes.

A simple, economical accurate and reproducible U.V. spectrophotometric method for the determination of Terbinafine Hydrochloride in both pure and pharmaceutical dosage form has been developed. Terbinafine Hydrochloride shows maximum absorbance at 223 nm with molar absorptivity of 9.378 x 103 lit/mole/cm. Beer’s law was obeyed in the concentration range of 0.6-4.2 ug/ml. The results of analysis were validated statistically and by recovery studies.

The Acumen eX3, a multiwavelength microplate cytometer, offers 405, 488 and 633 nm laser excitations in one instrument. This advancement significantly extends the range of fluorescent reagents that can be combined in multicolour, multiplexed assays over a wavelength range for excitation that is similar to that of white light source instrumentation. Thus, it permits seamless transfer of high content assay protocols, developed using CCD-based imaging devices, onto the Acumen eX3 for screening.

The Acumen Explorer combines the object-recognition capabilities of image-based systems with read speeds similar to that of bulk readers. Here, we demonstrate the powerful integration of an Acumen Explorer with the Kalypsys® Integrated Screening System, with capability to screen > 300,000 wells per day of high content data.