BS EN ISO 20184-1:2018 pdf download.Molecular in vitro diagnostic examinations – Specifications for pre-examination processes for frozen tissue Part 1: Isolated RNA.
All steps of a diagnostic workflow can influence the final analytical test result. Thus, the entire workflow including biomolecule stability and sample storage conditions shall be verified and validated. Workflow steps which cannot always be controlled (e.g. warm ischemia) shall be documented. A risk assessment of non-controllable workilow steps including their potential impact on the analytical test performance shall be performed and mitigation measures shall be established to enable the required analytical test performance.
Before or during the design of an analytical test, it should therefore be investigated and assured that the RNA profile(s) intended to be analysed is/are not compromised in a manner impacting the analytical test performance (e.g. by performing a time course experiment or study; see also Annex A).
Before tissues are stabilized by freezing, the RNA profile(s) can change e.g. by gene induction, gene down regulation and RNA degradation. These effects depend on the warm and cold ischemia duration and the ambient temperature before freezing. In addition, the described effects can vary in different donors/patients’ tissues.
Generally, the longer the duration of warm and cold ischemia and the higher the ambient temperature before freezing the tissue specimen, the higher is the risk that changes in the RNA profile can occur.
NOTE Intraoperative warm ischemia can result in more pronounced changes of RNA profiles than during postoperative cold ischemialZllal. RNA profiles can also vary, depending on the origin and type of tissue, the underlying disease, the surgical procedure, the drug regimen, and drugs administered for anaesthesia or treatment of concomitant disease and on the different environmental conditions after the tissue removal from the body.
As warm ischemia cannot be easily standardized, its duration shall be documented. When it is not possible to avoid cold ischemia, duration shall be documented and temperatures of the specimen container’s surroundings should he documented. Where the specimen is transported to another facility for freezing, the transport duration shall he documented and the ambient conditions should also be documented.
Safety instructions on transport and handling shall be considered (see ISO 15189:2012, 5.2.3 and 5.4.5 and ISO 15190).
During the whole pre-examination process precautions shall be taken to avoid cross contamination between different specimens/samples, e.g. by using single.use material whenever feasible or appropriate cleaning procedures between processing of different specimens/samples.
If a commercial product is not used in accordance with the manufacturer’s instructions, responsibility for its use and performance lies with the user.
5 Outside the laboratory
5.1 Specimen collection
5.1.1 General
For the collection of the specimen, the requirements (e.g. disease condition, specimen size) for the intended molecular examination (see also Clause6) should be considered.
See also ISO 15189:2012. 5.4.4.
5.1.2 Information about the specimen donor/patient
The documentation shall include the ID of the specimen donor/patient, which can be in the form of a code.
The documentation should include, but is not limited to:
a) the relevant health status of the specimen donor/patient (e.g. healthy, disease type. concomitant disease, demographics Ie.g. age and gender]);BS EN ISO 20184-1 pdf download.