How to stop disproportionation of a hydrochloride salt of a very weakly basic compound in a non-clinical suspension formulation.

Our objectives were to stabilize a non-clinical suspension for use in toxicological studies and to develop methods to investigate the stability of the formulation in terms of salt disproportionation. The compound under research was a hydrochloride salt of a practically insoluble discovery compound ODM-203. The first of the three formulation approaches was a suspension prepared and stored at room temperature.

Improved surface stability and biotin binding properties of streptavidin coating on polystyrene.

The ultimate nature of streptavidin to bind biotin tightly is widely utilized in many solid-phase based applications to provide a universal binding surface for biotinylated molecules. However, the preparation of the streptavidin coatings by passive adsorption may heavily alter the binding properties of native streptavidin and may not result in the best possible capture surface for demanding solid-phase assays. By introducing sulphydryl groups through primary amines in the protein, we have activated and conjugated native streptavidin into larger protein polymers resulting in high local binding density when coated on polystyrene.

Streptavidin-coated spot surfaces for sensitive immunoassays using fluorescence surface readout.

Direct measurement of time-resolved fluorescence from a washed surface of an immunoassay well constitutes an advantage compared with label development options involving signal generation in solution. Epi-fluorometric detection collects the signal from only a small part of the microtiter well's bottom surface and it is inadequate for the optimal assay sensitivity when using binding surfaces introduced by large coating volume. This study reports on the use of streptavidin-coated spots intended to condense the binding of the labeled antibodies to coincide with the excitation beam.

Utilization of recombinant Fab fragments in a cTnI immunoassay conducted in spot wells.

Objectives: To evaluate the performance of a new cTnI immunoassay utilizing site-specifically biotinylated recombinant Fab fragments on recently established spot wells.

Design And Methods: Two different cTnI-specific recombinant site-specifically biotinylated Fab fragments were produced. The performance of the new sandwich-type cTnI immunoassay in spot wells was evaluated in terms of binding capacity, assay kinetics and assay sensitivity and compared with a cTnI immunoassay carried out in conventional microtitration wells.