Highlights from the 2014 Applied Pharmaceutical Analysis conference.

The 10th annual Applied Pharmaceutical Analysis (APA) conference was held from 8th to 10th September in Cambridge, MA, USA. This year's APA conference focused on three different 'workshops' over the 3 days: Regulated Bioanalysis, Biotransformation, and Discovery. There was a great amount of information discussed by a variety of experts over the 3 days. This included, among other things; speakers from the US FDA discussing statute changes and guidelines, leaders from academic laboratories discussing innovation in bioanalytical tools, and industry scientists discussing current trends in the industry. The conference afforded attendees the opportunity to learn from the speakers during their sessions. In addition, there was ample opportunity for attendees and speakers both to learn from each other through informal interactions.

Resolution of matrix interference: quantitative and quasi-quantitative ligand-binding assays case studies.

BACKGROUND: Matrix effects pose a constant challenge in developing robust ligand-binding assays to be validated for use in nonclinical and clinical study support. When notable matrix effects of any kind are present, it can render an otherwise sound method ineffective. We present two case studies detailing the mitigation of observed matrix effects. METHOD: A dimeric protein was removed from unknown samples in an anti-therapeutic antibody assay through protein extraction. Nonspecific matrix effects in a quantitative ligand-binding assays were mitigated through development of a specialized buffer. RESULTS: The protein extraction method reproducibly reduced the artificially high responses of naïve samples, enabling the accurate detection of anti-therapeutic antibodies. Design of experiments was used to evaluate and select the optimal components and associated concentrations in order to reduce the observed matrix effect to acceptable limits. CONCLUSION: Our results suggest there are multiple techniques available for the bioanalytical scientist to mitigate both matrix effects in ligand-binding assays.

Comparison of four distinct detection platforms using multiple ligand binding assay formats.

Several detection platforms are available for ligand binding assays (LBA), each claiming superiority in sensitivity and dynamic range. However, little information exists in the literature directly comparing the various LBA platforms for quantitation. We have tested four common platforms to evaluate and compare the interchangeability of detection platforms by comparing sensitivity and dynamic range to a colorimetric LBA. The detection platforms compared are: colorimetric, chemiluminescence, time-resolved fluorescence (TRF) and electrochemiluminescence (ECL). Five different LBA protocols were tested with each of the detection endpoints. The assay protocols include the following ligand binding assay formats: direct binding, sandwich ELISA, competitive and cell based ELISA. We found that no detection platform consistently performed better than all the others and it was not possible to predict which platform would perform best for a given assay protocol. We also found surprising differences in assays (plate coating efficiency, low signal) which add to difficulty in choosing the best platform ad hoc. We propose here that in developing new assay protocols for detection of biotherapeutic agents, multiple detection platforms should be tested in order to forward the best assays possible and for the right reasons.