- Ease of use
- After sales service
- Value for money
A CE-based analytical system configured optimally for the methods development process, where a focus is placed on spectral analysis and the automation of separation strategies. The system includes a P/ACE MDQ configured with both a photo diode array and selectable-wavelength UV/Vis (200, 214, 254 and 280 nm filters included) detector, UV source optics, temperature-controlled sample storage module and 32 Karat™ Software configured on an IBM personal computer. Installation Qualification, Operation Qualification 1 (OQ1) and documentation to aid in software validation is also included.
Multi-format Sample Introduction
Automated Sample Introduction directly from 96 well plates, 2ml autosampler vials, PCR vials and 0.5 ml tubes. Automation is certainly a means by which many laboratory bottle necks may be reduced. One of the major bottle necks is in sample handling. The use of 96 well plates as a sampling vessel not only increases system capacity but allows compatibility with automated sample preparation devices which utilize the 96 well plate format. Additionally, 2 ml vials (which are autosampler industry standards) may be used; or sampling can be achieved directly from PCR vials and microfuge tubes.
Methods Development with 36 Position
Methods Development through a 36 position buffer pair array independent from sampling vials. When optimizing a methods development strategy or scouting for successful separation conditions; the buffer pH, concentration and ion type plays a dramatic role in the process. An array of 36 buffer pairs independent from the samples allows your methods development strategies to be automated while maintaining system sample capacity. To ensure proper separation one must match both the inlet and outlet buffers requiring the necessity of buffer pairs.
Multiple Separation Modes
Modes of separation include: Voltage, Current, Power, Pressure and Vacuum. All electrophoretic separations allow the programming of both step and linear gradients along with the simultaneous application of pressure or vacuum on both ends of the capillary. Voltage gradient programming is beneficial for gel-sieving techniques improving separations over a wide range of fragment sizes. This is especially critical for the separation of nucleic acids. The application of simultaneous voltage and pressure is beneficial for the high efficiency mobilization of proteins during iso-electric focusing as well as detecting material not migrated off the capillary. Also, several CEC methods have specified the use of simultaneous pressure applied to both inlet and outlet reservoir. This system is compatible with those methods.
High Sensitivity UV Detector
Modular High Sensitivity Selectable Wavelength UV Detector utilizing up to seven filters in an assembly which allows wavelength changes during a run. Detector sensitivity in capillary electrophoresis is critical since small mass loads are introduced and small detection pathlengths are used (governed by the capillary dimensions i.e. 25 - 200 um). Fixed wavelength detection in a filter wheel assembly maximizes detector sensitivity yet still allows wavelength changes during a run. In a Q.C. or regulated environment it is beneficial to "lock-down" a method once it is developed in order to retain the integrity of the data. The P/ACE™ high sensitivity UV detector may be configured with a "single" wavelength from a filter traceable to NIST making both the instrument certification and method validation much simpler. Additionally the system employs complete fiber-optic technology bypassing the necessity of an optical bench. This lowers the noise on the detection system (by removing reflective surfaces where energy loss can occur) and simplifies the system making it more rugged for routine use. Diode array is an essential detection tool for methods development work, but will reduce the lifetime of a "coated" capillary. Therefore, once a method is developed and is in routine use it is beneficial to switch to a UV detector where the capillaries will last longer.
Dual Wavelength LIF Option
Optional - Dual Wavelength Laser-Induced Fluorescence (LIF) Detection System. High sensitivity laser-induced fluorescence detection extends the capabilities of capillary electrophoresis for the analysis of carbohydrates and nucleic acids and other compounds which either naturally fluorescence or that can be made to fluoresce through sample derivitization. LIF provides both selectivity and sensitivity to any analysis and typically yields 500 x better sensitivity than UV for compounds which fluoresce. The P/ACE™ MDQ LIF detector is modular and will allow simultaneous excitation using two laser sources. And with the second channel option installed, it will collect simultaneously emissions from two different wavelengths. This is important where you wish to run your sample and standard together in the same run, using two "colors" to discriminate between the two species.
GLP/CGMP Compliance Features
32 Karat Software includes the following GLP/CGMP compliance features: 1) Original method is stored with sample data. 2) Raw data cannot be overwritten. 3) The instrument logs all major events 4) Software security includes password protection with multiple levels of operator access. Many laboratories are mandated by law to follow current good manufacturing practices (CGMP) and good laboratory practices (GLP) the 32 Karat Software has many features which are geared towards the maintenance of data integrity. With the GLP flag turned on, sample data and methods parameters cannot be overwritten or overridden, ensuring the data that was generated was as described. To track instrument operation, all events including errors are logged onto the system. To provide security of operation users may be coded to different security levels with selected access to: system configuration, methods programming, data reprocessing, specific instrument operation and data comparison. All of these features can be used to "lock down" the system for regulated use or logged in as a "toggled off" state in laboratories where flexibility of operation is the critical issue.
Specialized CE Calculations
32 Karat Software provides specialized CE calculations including: Apparent Mobility, Mobility, Corrected Peak Area, Molecular weight and Iso-electric Point. The software also includes system suitability which will use these calculations in actuating suitability decisions. The suitability algorithms are capable of triggering re-injections, methods pausing, methods aborting or running shutdown methodology upon failure. Capillary electrophoresis requires specialized data handling. Mobility calculations establish the identity of a compound independent from changes in electroosmotic flow, voltage, temperature and column dimensions. This can be very useful in compound identification and method validation especially when comparing data between different laboratories where analytical conditions may vary slightly. However, to calculate this value one must utilize actual voltage values, not simply programmed values. Since CE detection is "on-column," it is important that peak area be normalized to a compounds velocity. When characterizing a protein it is essential to be able to calculate its molecular weight and iso-electric point.
Sample Tray Temperature Control.
Temperature regulation controls samples independently from the electrophoresis buffers. Sample temperature maintained from 4° to 60° C. Sample temperature control is beneficial in minimizing the degradation of temperature-labile compounds and controlling reaction rates when looking at enzyme kinetics. However, it is essential that when regulating the sample temperature to ensure that the temperature of the electrophoresis buffers remains unaffected. Lowering the temperature of buffers with detergents, high salts or chiral additives will result in precipitation. Furthermore, temperature gradients arising from cooled buffers may negatively impact on separation efficiency, peak symmetry and even reproducibility.
Electrokinetic, Pressure and Vacuum
Sample introduction by all three injection modes; Electrokinetic, Pressure and Vacuum with variable control of all introduction parameters. All sample injection modes are equally accessible from either end of the capillary. In moving validated methods from a development lab to a routine use environment, the issue of compatibility of methods transfer is always at issue. An instrument designed to operate with all commonly used sample introduction modes and the capability to dial in the parameters (i.e. injection pressure or vacuum), allows greater ease in transferring methods developed on other instrument brands. Being able to inject from both sides of the capillary, provides a rapid low resolution screen and a high resolution analysis all from the same capillary.
Fluid Delivery with Variable Pressure and Vacuum
Fluid Delivery provided by both variable pressure (0.1 to 100 p.s.i) and vacuum.
Conditioning of the capillaries is accomplished by moving specific volumes of electrolytes, regenerants and cleaning solutions through the capillary. The P/ACE™ MDQ is designed to operate with all commonly used rinsing protocols and the capability to regulate these parameters (i.e., magnitude of applied pressure or vacuum), allows greater ease in transferring methods developed on other instrument brands by keeping conditions consistent.
Guards against system obsolescence and lowers cost by allowing the use of multiple detectors on a single instrument platform. For example a methods development platform may be rapidly reconfigured to a routine use platform by changing the detector module and locking down the software methods.
Diode Array Detection
Modular Diode-Array Detector. The P/ACE™ MDQ Diode Array detector allows real time display, collection and analysis of electropherograms from up to four different wavelengths simultaneously with all wavelengths selected within a scan range extractable for integration after the run. Diode-array provides high resolution spectral scanning detection for capillary electrophoresis. Capillary electrophoresis generates peak efficiencies much greater than HPLC making scanning with traditional "fast-scanning" detectors impractical. Diode-array detection provides high quality spectral information without compromising resolution. The exceptional spectral resolution provided allows library search algorithms to more accurately identify a compound even with large analyte concentration differences. With 32 Karat Software, four channels of data can be viewed, collected and analyzed in real-time. While any wavelength in the scan range may be viewed during a run and selected for extraction and analysis after the run. This allows an operator to make methods development decisions in real time as all data may be accessed.
CAESAR Integration Algorithms
Lower limits of quantitation with CAESAR Integration algorithms.
CE by its nature separates components based on differences in their inherent mobilities and as such produces peaks which are typically non-gausian in distribution. This a function of the analytes mobility with respect to the mobility of the separation electrolyte. CE baselines also tend to demonstrate more perturbations and drift as lower detection wavelengths are commonly used challenging traditional integration algorithms. The CAESAR algorithm has been optimized for CE data reduction using moving median data filtering to lower the limits of quantitation. Up to five fold improvements in LOQ's have been documented by using this means of data reduction which is optimized for CE analysis.
Automatic Standards Co-Injection
Automatic co-injection from multiple standards in combination with the sample injection is offered.
Sample injections can be automatically spiked with reference standards for positioning or for positive identification. This is useful to help minimize errors resulting from sample matrix effects. Additionally, with high salt samples it may be necessary to do multiple injections within the same run in order to employ an electrokinetic salt elution step. Practical examples of this include the electrokinetic injection of PCR* samples directly after amplification. The interfering salts and metals would need to be be removed through a sample handling step if one were not able to perform an electrokinetic elution from ddH20 prior to sample introduction. Additionally, once a sample table has begun the data that is generated may indicate the necessity to run new sample combinations. On the fly sample table editing may be accomplished with the 32 Karat Software allowing the addition of new samples to a running sequence.
Mercury Lamp Calibration of DAD Detector
The P/ACE MDQ™ system uses an internal mercury lamp to calibrate the Diode-array detector providing excellent wavelength accuracy (± 1 nm) and precision. This ultimately improves the ruggedness and reproducibility of the system.
Application notes and news
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Member since 2011
University of Kansas
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"reliable instrument but when maintenance is needed they are very slow at responding and very expensive when they do come."
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Member since 2006
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"The equipment is well designed with good automation capabilities, but liquid coolant can be a limitation for Teflon coated capillaries."