DIN Standards Committee Water Practice
DIN 38411-25
German standard methods for the examination of water, waste water and sludge - Microbiological methods (group K) - Part 25: Protocol for the validation of alternative confirmation procedures and for verification of validated alternative confirmation procedures (K 25)
Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung - Mikrobiologische Verfahren (Gruppe K) - Teil 25: Arbeitsvorschrift für die Validierung von alternativen Bestätigungsverfahren und für die Verifizierung von validierten alternativen Bestätigungsverfahren (K 25)
Overview
Microbiological testing of water is currently performed according to the methods specified in regulations which, depending on the method, require confirmation of the detected microorganisms. This document has been prepared in order to enable the use of alternative methods for the confirmatory identification of microorganisms in water analysis. Alternative methods validated according to this document may also be used as confirmation procedures within the scope of existing reference methods and replace existing culture-based methods in part or as a whole. If the application and compliance with standards are mandated by law, for example in the Drinking Water Ordinance, then alternative confirmation procedures may be used if this is permitted by a note or corresponding information in the reference method. This document specifies the general principle and technical protocol for the validation of alternative confirmation procedures in microbiology. This document compares the results of the alternative confirmation procedure with those of the confirmation procedure of a reference method or, if required, a reference confirmation method. This document applies to the validation of alternative confirmation procedures for the analysis (detection or quantitative determination) of isolated microorganisms in: drinking water, groundwater, surface water, and wastewater; utility water, process water, and sanitary water; other waters; and sludge. Validated alternative confirmation procedures may be used to replace the confirmation procedure (in whole or in part). This also implies that the alternative confirmation procedure may be used in the reference method or in a method equivalent to DIN EN ISO 17994 [4], provided that an isolation agar is used in that method, following successful validation in accordance with this document. This document is applicable to bacteria and fungi in particular. Applicability to other (micro)organisms shall be assessed on an individual case basis. In addition, this document applies to the validation of alternative typing methods, where the reference method may be, for example, a serological method or a molecular method (for example, for the typing of Shiga toxin-producing E. coli). Validation studies according to this document are primarily intended to be carried out by organizations or expert laboratories involved in method validation. However, they may also be used by an individual laboratory, in particular for in-house validation under certain conditions. Furthermore, this document specifies the protocol to be used in the verification of validated alternative confirmation procedures for implementation in the user laboratory. These technical protocols for the verification of validated confirmation procedures are also specified. This document has been prepared by Working Group NA 119-09-03-03 AK "Alternative Bestätigungsreaktionen in der Mikrobiologie" ("Alternative confirmation reactions in microbiology") of Working Committee NA 119-09-04 AA "Microbiology" ("Microbiology") of Section NA 119-09 FBR "Wasseruntersuchung (CEN/TC 230, ISO/TC 147)" ("Water Analysis (CEN/TC 230, ISO/TC 147)") at DIN Standards Committee Water Practice (NAW).
Responsible national committee
NA 119-09-04-03 AK - Alternative confirmation reactions in microbiology
