3-D printed aseptic injection system for capillary electrophoresis

Area of Science:

• Analytical Chemistry
• Microbiology
• Biotechnology

Background:

• Capillary electrophoresis (CE) is effective for separating complex mixtures, including intact viable organisms for microbiome analysis.
• Existing sample introduction systems lack ease-of-use, cost-efficiency, and aseptic capabilities for microbiota analysis.
• Sterile injection is crucial for accurate analysis of microbial communities.

Purpose of the Study:

• To develop and evaluate a novel manual injection block for aseptic sample introduction in CE.
• To improve the ease-of-use and cost-efficiency of CE for analyzing viable microorganisms.
• To facilitate sterile analysis of microbiomes using CE.

Main Methods:

• Development of a manual injection block with an internally threaded collar and recessed capillary/electrode for contamination prevention.
• Integration of an externally threaded vial holder for autoclavable sample tubes.
• Performance evaluation using capillary zone electrophoresis (CZE) with laser-induced fluorescence detection of fluorescein and viable Escherichia coli.

Main Results:

• The new injector facilitates sterile analysis of viable organisms via CE.
• Fluorescein detection showed linear responses across four orders of magnitude with low limits of detection (6 pM hydrodynamic, 8 pM electrokinetic).
• Separation of *E. coli* demonstrated a four-fold improvement in zone width compared to previous designs, with comparable migration times.

Conclusions:

• The developed manual injection block provides a cost-effective and user-friendly solution for aseptic sample introduction in CE.
• This innovation enhances the capability of CE for analyzing viable organisms and advancing microbiome research.
• The system's design ensures sterility and improves the resolution of microbial separations.