Capillaries for capillary electrophoresis (CE) are critical components that directly influence electroosmotic flow (EOF), separation efficiency, and reproducibility. This category includes bare fused‑silica capillaries and surface‑modified capillaries designed to support stable, controlled separations across a wide range of CE methods and operating conditions.
Proper capillary selection is essential in CE, as control of EOF affects migration time, resolution, and method robustness. The capillaries in this category are manufactured with tight dimensional tolerances and consistent surface characteristics to support reproducible analytical performance.
Bare Fused‑Silica CE Capillaries
Simplus™ bare fused‑silica capillaries are designed specifically for capillary electrophoresis applications where native EOF is desired. These capillaries are manufactured with controlled internal diameter concentricity, producing more uniform electroosmotic flow and consistent migration times.
Simplus™ capillaries are available in multiple internal diameters and lengths, including extended‑length “Big Pack” formats supplied on reels, supporting high‑throughput laboratory use, method development, and routine analysis.
Controlled Flow Capillaries™
Controlled Flow Capillaries™ are surface‑modified to provide reproducible, pH‑independent electroosmotic flow. These capillaries are covalently bonded with an acrylamide‑derivative surface, allowing EOF to remain stable across a broad pH range (approximately 1.5 to 8.0).
Compared to bare fused‑silica capillaries, Controlled Flow Capillaries™ deliver faster and more reproducible flow rates, supporting improved method robustness where EOF variability would otherwise impact separation performance.
Zero EOF Capillaries™
Zero EOF Capillaries™ are engineered to produce minimal to no electroosmotic flow, even under high‑voltage conditions. These capillaries are covalently bonded for chemical and mechanical stability and are commonly selected for applications where EOF suppression is required to achieve separation selectivity.
Zero EOF Capillaries™ are typically used across a pH range of approximately 2.0 to 8.0 and do not require changes to analytical methodology beyond standard capillary conditioning procedures. They are supplied with certificates of analysis documenting EOF characteristics to support method validation and reproducibility.
When using surface‑modified capillaries, it is recommended not to use heat‑based methods to create optical detection windows, as this may compromise the bonded surface.
Selection & Best Practices
CE capillary selection should consider:
Desired electroosmotic flow behavior
Buffer composition and pH range
Applied voltage and separation length
Detection requirements and window preparation method
Correct handling and preparation of CE capillaries plays a significant role in performance and longevity.
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