SPADA Draft Documents

from different sources and are often not qualified/certified to the same set of standards, making it 24 difficult for results to be confidently compared. 25 One way to limit and monitor the genetic drift in laboratory handled strains is by encouraging 26 researchers to carefully document the histories of bacterial cultures and routinely screen them for 27 divergent genotypic or phenotypic signatures. This guideline establishes a framework for 28 investigators to use in documenting the relationships among microbial cultures used in well- 29 documented studies. 30

2.0 Concepts and Definitions

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( a ) An extensible study is a research program whose results and conclusions are expected to

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apply equally to test and index cultures.

( b ) In an extensible study, the test culture is the microbial culture that is being evaluated.

34 The index culture is the culture to which the results are to be applied. 35 36 well-documented lot/batch/subculture number and production record. 37

( c ) Both the test and index cultures must be traceable cultures , meaning that each has a

( d ) Extensible studies are generally supported by sponsors , who establish the experimental 38 objectives, culture producers, who manufacture and characterize the study’s traceable cultures, 39 and performers, who conduct the study. These roles can be filled by the same or different 40 organizations. However, each role has specific responsibilities with respect the culture 41 verification process. 42 ( e ) Culture verification is the process by which the species in a test culture is shown to be 43 sufficiently related to that in an index culture to allow the meaningful extension of experimental 44 results from one culture to the other. The relationship between the test and index cultures should 45

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