Test system

The test system of assay documents lets you set up sophisticated tests to validate the suitability of your assays and plausibility of results. The Microbial Assays for Antibiotics Package provides a range of tests for each document type.

Test system logic

The following settings let you modify the role of individual tests within the test system:

  • Test level (assay or sample)

  • Severity level of the test

  • Scope of the test

Test level (assay or sample)

The test system distinguishes between assay suitability tests and sample suitability tests.

  • Assay suitability tests define criteria that decide whether the entire assay run is to be accepted or rejected.

  • Sample suitability tests define criteria that decide whether individual samples are to be accepted or rejected.

Tip: When you create a new assay document, it does not contain any tests. You add tests as child elements under Assay suitability tests or Sample suitability tests. The tests available for the current document type are listed in the Creatable elements pane.

Severity level of the test

Every test has a severity level setting. When you add tests to an assay document, their severity level is set to 'Warning' by default. For each test, you can select one of the following severity level options:

Severity level Description

Reject

If the test fails, interpolated concentrations and additional calculation results are reported. For reporting the overall test result, the test is considered 'Failed (rejected).'

Warning

If the test fails, interpolated concentrations and additional calculation results are reported. For reporting the overall test result, the test is considered 'Failed (warning).'

Information

If the test fails, interpolated concentrations and additional calculation results are reported. For reporting the overall test result, the test is considered 'Passed (info).'
Note: When you calculate assay documents of the Microbial Assays for Antibiotics Package, interpolated concentrations and additional calculation results are always reported, even when tests fail, irrespective of the severity level settings of failed tests. Reporting in other PLA 3.0 add-ons may differ.

Overall test result

Assay results include an overall test result that combines the results of all tests into a single value. The following table explains how the severity levels of individual failed tests influence the overall test result:
Overall test result Failed tests of severity level 'Reject' Failed tests of severity level 'Warning' Failed tests of severity level 'Information'

Passed

0

0

0

Passed (info)

0

0

≥1

Failed (warning)

0

≥1

any number

Failed (rejected)

≥1

any number

any number

For an example on how severity levels can influence the overall test result, see the Define a test system topic.

Scope of the test

When you add tests that are appropriate for all assay element types, PLA 3.0 runs these tests by default for all assay elements in the assay document. You can restrict the scope of individual tests to have them run only for particular assay element types or for particular assay elements:

  • Assay element type scope: Lets you select a particular assay element type, that is, Standard, Test sample, or Control. The test is then run for all assay elements of this particular type, but not for other assay elements in the assay document.

  • Assay element scope: Lets you select a particular assay element, that is, the Standard, a particular Test sample, or a particular Control. The test is then run for this particular assay element, but not for other assay elements in the assay document.

Note: Some test types are intended for particular assay element types. The scope of these tests is restricted by default to the intended assay element types. They are not run for assay elements of other types.

Available tests

The following tests are available for Turbidimetric assay (USP <81>/JP 4.02) documents:

  • Test: Response range

  • Test: Step - Standard deviation

  • Test: Step - Relative standard deviation CV (%)

  • Test: Combined standard deviation of the standard

  • Test: Parameter/property point estimate

  • Test: Coefficient of determination (R²)

  • Test: Potency of the working sample

  • Test: Absolute potency

  • Test: Relative potency (percentage of reference concentration)

Severity levels and overall test result

The following two images indicate how the severity level of failed tests in a simple test system influence the overall test result. The assays of both images have a single Test sample and a Standard with a 5-step concentration sequence. Both images show the suitability test results for the Test sample as they are provided in the dashboard.

Both assays passed the sample suitability test, but failed both assay suitability tests due to problems with the Standard sample. The assay of the first image had the severity level of both assay suitability tests set to 'Information.' The assay of the second image had the severity level of one assay suitability test set to 'Information' and the other to 'Warning.'

Figure 1. This assay failed both Assay suitability tests. The Severity level of both tests was set to 'Information'
Figure 2. This assay also failed both Assay suitability tests. The Severity level of one of these tests was set to 'Information.' The Severity level of the other was set to 'Warning'

For details on how to set up such a test system, see the Define a test system topic.