- Fragment Analyzer
- CE Review
- Software &
- Reagents &
Capillary Electrophoresis Review
Parallel Capillary Electrophoresis:
Description of Technology
Advanced Analytical's parallel capillary electrophoresis (CE) technology enables electro-driven analytical
separations of DNA and RNA with on-line, simultaneous LED-based fluorescent detection.
- exchangeable capillary array assembly.
- fixed optical detection platform.
- high-voltage power supply.
- fluid pumping system.
- automatic tray positioning system.
Customized software is tailored for specific applications and provides instrument control, data acquisition, and data analysis. End-users may view the CE separations as electropherograms, or as digital gel images.
The instrument is designed to handle either a 12 capillary array which can access all wells of a 96-well plate, 12 samples at a time or a 96 capillary array, able to sample all positions in one injection. Standard capillary dimensions are 50μm inner diameter (i.d.) and 200μm outer diameter (o.d.).
Anyone who was worked with agarose or acrylamide gel electrophoresis knows about the trade- off between speed vs. resolution. If you want high resolution; you use a long box. If you want answers quickly, you use a short box. Likewise with the Fragment Analyzer™ Automated CE System: various capillary lengths can be used, depending on the application, required resolution and desired speed of analysis. Longer arrays provide resolution down to 2 bp for fragments under 300 bp in length. Shorter arrays still provide good resolution with run times as fast as 15 minutes.
The inlet side of the capillary array is arranged in an 8 x 12 format with electrodes placed side-by-side with each capillary, allowing for direct injection via vacuum or voltage from standard 96-well plates. The capillaries are aligned in parallel in the detection window, which is positioned between the LED light source and the detector assembly. The outlets of the capillaries are bundled to a common reservoir where they are connected to a ground. The capillary arrays are modular in nature and a new capillary array can be exchanged in less than five minutes.
Room temperature air is circulated around the capillaries to modulate the temperature during the CE separation. Technology Schematic (12 capillary Version shown)
The optical platform consists of an LED light source (470nm excitation), camera lens and a CCD detector. Fluorescent light from the LED that passes through the windowed part of the capillary array, exciting the intercalating fluorescent dye present in the gel matrices, is focused on through the camera lens and spatially imaged onto the CCD detector. The capillary array is imaged continuously, providing real time, on-line detection of the CE separations.
The 20 kV, 6 mA total current high voltage power supply provides the appropriate voltage for electrokinetic sample injection and electrophoresis. The recommended operating limits are +/-16 kV, 3 mA total current (30μA per capillary).
A high-quality syringe pump provides controlled pressure or vacuum to the outlet reservoir of the capillary array. The ability to use vacuum is unique to the instrument. Vacuum injection can be used to inject samples without concern of salt interfering with the uptake of nucleic acids. Additionally, 2 modes of injection allow greater flexibility on the system and control of experiments when needed.
The instrument provides space for up to six 96-well plates. The positions of the stages are typically assigned to a (from the top) inlet/run buffer tray, waste tray, marker tray and three sample trays, respectively. When marker fragments are added directly to the samples (as designed in the NGS Fragment Analysis Kit, RNA Kits, and genomic DNA Kits), 4 sample trays (384 samples) can be loaded onto the instrument at one time. For automated sample addition and robotic access to the tray positions, modified (open faced) drawers are available.
Operational software provides complete automation for performing capillary conditioning, sample injection, electrophoresis separation and data processing while the analytical software, PROSize™ allows user to quickly review and assess data in a digital format.