Better sensitivity in SDS-protein electrophoresis

Bio-Rad Laboratories has released a technical note (tech note 5719A) entitled: Experion automated electrophoresis system: enhancing sensitivity in SDS-protein electrophoresis

Capillary electrophoresis (CE) is a commonly used means for separating sodium dodecyl sulphate (SDS)-proteins but a drawback is the requirement for extensive capillary preparation before each injection, which increases analysis time and reduces throughput.

Automated microscale electrophoresis systems provide a rapid and convenient alternative to conventional CE instruments for the separation of SDS-proteins.

For example, the Experion automated electrophoresis system is a chip-based separation system that can process ten samples in 30 minutes.

The protein mass range covered by the system is from10-260kD, and the resolution is similar to that of a 4-20% gradient gel.

The system employs a dynamic staining-destaining chemistry, with fluorescence detection that provides sensitivity comparable to colloidal Coomassie staining.

To enhance the sensitivity of the Experion system for detection of low-level impurities in preparations of biotechnology products, a method for prelabeling proteins with a fluorescent dye was investigated.

The technical note describes prelabeling proteins with the fluorescent tag Alexa Fluor 647 prior to analysis with the Experion system, achieving an 80 to 500-fold enhancement in sensitivity compared to the conventional Experion method.

A comparison of band intensities using the Experion system and SDS-Page demonstrates that the Experion system can achieve detection limits comparable to those of silver staining of proteins resolved on a polyacrylamide gel.

Availability.

Tech note 5719A is available either from a local Bio-Rad sales office or it may be downloaded at.

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