Impact of the sample matrix composition on the signal enhancement in the capillary electrophoretic separation of poliovirus samples

The development of capillary electrophoretic applications aiming to provide reliable stability assessment of viral suspensions, to detect subviral particles from cell extracts or to study the interactions between virus particles and various biomolecules, cannot be done without a thorough understanding of the sample matrix contribution to the observed electrophoretic behaviour. The present study thoroughly investigates the effect of the sample matrix on the electrophoretic behaviour of poliovirus injected as sample plugs of 1%, 5% and 12% effective capillary length. The effect of the sample matrix for three different poliovirus batches was evaluated. Additionally, simulated samples, obtained from concentrated poliovirus suspensions of high purity and diluted with commonly used lab buffers in order to obtain samples with either high or low conductivities, were also investigated. The goal of the study was to obtain a better understanding of the effect of the sample matrix on the signal enhancement, in order to define a general approach allowing a repeatable capillary electrophoretic (CE) separation of poliovirus from complex samples. This study clearly demonstrates that the sample matrix has an important influence on the sensitivity of the CE poliovirus separations. Translation of these observations into routine practice involves several compromises and a set of rules in order to reduce day-to-day variation and to maximize sensitivity.

The effect of the small increase in sample matrix conductivity on the electrophoretic profile of the poliovirus suspensions. Separation conditions: uncoated fused silica capillary 40 cm effective length; 100 mM borate buffer pH 8.3 with 25 mM SDS; detection wavelength 205 nm. Sample: highly purified poliovirus suspension after matrix removal and concentration by ultrafiltration, diluted using the borate buffer pH 8.3 of specified concentration, injected as 12% plug.Figure optionsDownload as PowerPoint slideHighlights
► First study of the sample matrix impact on the CE signal enhancement of viruses.
► The effect of sample matrix variations from growth and purification is discussed.
► Sample matrix importance for the CE sensitivity of poliovirus separations is shown.
► Influence of the sample matrix on the preconcentration mechanism is examined.
► Approaches for repeatable and reliable CE separations of poliovirus are indicated.