Reference standards validation

Control All control points starting with the basic raw materials right through to the finished product must be identified. Descriptions of the specifications, test methods, reference standards, and methods validation data should be included. 

Indeed, there are potentially several different levels to approach standardization of IHC For the greatest scientific rigor, it is required to perform serial experiments based upon the hypothesis mentioned above to investigate and validate, if possible, standardization of IHC based on the AR technique (Chapter 5 in detail). Another approach, that may be combined with AR, is the systematic development of Quantifiable Internal Reference Standards (QIRS) that will allow assessment of the degree of protein degradation... 

The benefits of producing good data are therefore broad and impinge on all of our daily lives, whether it is food, environment, health or trade. Laboratories that produce valid measurements have a higher status in the analytical world, since they produce data that are demonstrably traceable to a reference standard and reliable, with the cost of correcting bad data being lower. This means that such laboratories have a better chance of competing in the open market. 

A rationale should be generated to explain and support the reasoning for validating the selected parameters. The use of reference standards during validation helps to reinforce the reliability of the analytical method developed. The conditions of how a test is performed may have a strong influence on the results. These conditions have to be recorded and followed. 

The results are extended (move 3) in step 4, Procedure Validation. The extended information informs the viewer that (1) results were linear and reproducible and (2) the technique also works with a certified reference standard (Table 2). These results build logically on the principal finding of the work, that with saponification RGBs can be detected in full-fat milk. 

The use of standard solutions, reference standards, and quality control samples, whether prepared by the laboratory or purchased commercially, is essential to valid analyses of test and control article/carrier mixtures and biological fluids (blood, serum, plasma, etc). 

Authentic sample a purified and characterized sample of a related substance. Unlike reference standards, authentic samples may not be of high purity. However, the purity of an authentic sample has to be determined before use. Authentic samples are used in method development to identify related substances in the analysis. In addition, they are used extensively to prepare the spiked samples in method validation. 

To establish safety and to ensure consistency, the complete chemical composition should be provided for every material used in the manufacture of a packaging component. Test results from appropriate qualification and characterization tests should be provided. Adequate information regarding the tests, methods, acceptance criteria, reference standards, and validation information should be also provided. 

Satisfactory results for a method can only be obtained with well-performing equipment. Therefore, before an instrument is used to validate a method, its performance should be verified using universal standards (47). Special attention should be paid to the equipment specifications that are critical for the performance of the method. For example, if detection limit is critical for a specific method, the detector specifications for baseline noise and the response to the specified compounds should be checked. Furthermore, any reagent or reference standard used to determine critical validation parameters should be double-checked for accurate composition and purity. 

Key words Traceability chain Metrology in chemistry Reference material Amount standard Validation... 

R, the NARL reference analytical value (accompanied by measurement uncertainty estimate) traceable to SI through the validated test method used and the pure substance reference standards used to calibrate the measuring instrument... 

To make sure that all the values used in the measurement equation and all other fixed values used in the measurement are traceable, it is necessary to establish procedures for calibration of the measuring equipment or for controlling fixed values, and for ensuring the calibration, certification or control of all the references used in the measurement. Calibration, together with validated methods, is therefore the key to traceability. In practice, it is recognised that calibrated and certified reference standards are not always available, but it is always necessary to establish sufficient control through the appropriate choice of measurement standards. 

For chemical measurements with a linear calibration function, traceability of results can be formally established without great expenditure if the calibration is based on suitable reference standards and the linear regression is performed as shown above and (statistically) validated. The use of reference materials as samples make it possible to establish the traceability of a new analysis protocol by using an existing analysis method. 

Before an analytical method can be validated, it is necessary to qualify those materials that will serve as reference standards. To allow for expeditious validation, it is important to source and/or synthesize and characterize... 

The Y tube transmits pressure equally to the reference device and the device to be tested. Using the bulb connected to the Y pressure is increased to 300 mmHg and then lowered by 10 mmHg. Recording the pressure on each device validates the accuracy of the aneroid or electronic device, Any device that differs by more than 3 mmHg from the mercury or reference standard is considered to be out of calibration and should be removed from service. 

Validation should be performed on three separate days to compare precision by analyzing three replicates of reference standards under identical conditions (once again the acceptance criteria should be a prespecified coefficient of variation). 

An in vitro bioassay can be designed in several ways, but requires statistical validity. A one point assay is not valid. The bioassay should be designed to consider factors that introduce variability, and the analysis should test such variability. A measurement series of a test sample should be compared to an equivalent series of the reference material, carefully considering the comparisons between the linear portions of the dose-response curves (Mire-Sluis et al., 1996). To test validity of a bioassay inter- and intra-assay variability should be considered in both preparation, and in the case of multiwell plates, the variability between each plate. To reduce the positional effect in plate tests, it is advisable to distribute the points on the curves randomly and also to include a reference standard in each plate (Gaines-Das and Meager, 1995). One of the most widely used techniques to validate a bioassay s performance is to include internal duplicates. The data arising from the comparison can be important in assessing the test s variability. 

Increase in the proportion of patients identified by MRI that benefit from treatment Increase in the proportion of patients with a specific stroke pathology identified by MRI Sensitivity, specificity, and prospective values of MRI for a specific stroke pathology compared to a reference standard, assessment of validity... 

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