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Beckman Coulter’s DU 800 Spectrophotometer is a PC controlled system intended for use in quantitative and qualitative analysis in biological and industrial procedures that require spectrophotometric measurements in the UV and visible region of the electromagnetic spectrum. If the instrument is used in a manner other than as described, the safety and performance of the instrument can be impaired.
The spectrophotometer operates in the wavelength range of 190 to 1100 nm and has a bandwidth of less than or equal to 1.8 nm. The focused micro-beam design provides a wide linear range and other specific benefits for small volumes and precious samples. Various accessories are available to address micro-volume samples and individual application requirements.
The control of the instrument, data handling, and data reduction capabilities are contained within the confines of the PC. The frame-oriented software provides a convenient and user-friendly interface and, therefore, ensures a quick learning curve. The PC requires Microsoft Windows 2000 or later as the operating system.
Optical Principle
This spectrophotometer is a single beam instrument. Light from both sources enters the monochromator where it is dispersed by a concave holographic grating. Monochromatic light exits the monochromator and illuminates the sample. The amount of light that passes through the sample is measured by a single photodiode detector. The focal point of the beam in the sample compartment is on the right-hand side. All sampling accessories position the sample at the focal point for best performance with regular samples and micro-samples.
The exclusive micro-focused beam of the system delivers the full energy of the beam to your microsample (e.g.: using a 50 uL microcell) to provide highly accurate and reproducible measurements of small and precious samples including DNA and proteins. A standard beam can lose as much as 80 percent of its intensity when applied to a microvolume sample, resulting in a significantly smaller dynamic range and lower sensitivity. The company provides a wide range of unique microvolume accessories, such as single, six, and twelve position cell holders as well as microcells for greatest convenience and performance.
The following applications are available with the software installation:
Fixed Wavelength – Performs Absorbance or %Transmittance readings for up to 12 wavelengths simultaneously. A factor or custom formula may be applied to calculate final results.
Wavelength Scan – Performs wavelength scans in Absorbance or %Transmittance. Acquired scan data are stored and may be used for various manipulations and calculations. Includes the calculation mode to add, subtract, multiply and divide spectra.
Kinetics/Time – Simultaneously measures and analyses up to 12 rate reactions. Data can be reviewed in real time and automatically calculated and printed. The rate of the kinetic reaction is reported using a linear regression.
Nucleic Acid Analysis – Determines protein impurity in nucleic acid samples based upon the ratio of readings at two wavelengths with a choice of background correction. Protein and nucleic acid concentrations can also be calculated using the Warburg and Christian1 coefficients.
Single Component Analysis – Determines the concentration of unknowns by either linear or non-linear (quadratic) regression and provides statistical analysis for the standard curve. The standard curve can have up to 30 standards. The operator can re-run any standard, remove or add standards, and have the instrument re-calculate the curve.
Performance Validation – Provides a simple procedure to verify the performance of the instrument without standards or samples. Tests include: wavelength accuracy and repeatability, resolution, baseline flatness, noise, and stability.
In addition, the “rapid” modes RediRead and RediScan are available. These provide the user with a fast and easy way to take readings at fixed wavelengths or to make wavelength scans.
The standard software provides all available features to support regulations such as 21 CFR Part 11 Electronic Records; Electronic Signatures.
Filed Under: Drug Discovery
