Our ring test aims to validate genetic methods for the characterization of soil invertebrate communities. These genetic methods comprise

• DNA extraction and
• Metabarcoding PCRs of the obtained DNAs

and are intended to be used in soil quality assessment based on bulk invertebrate samples (obtained according to ISO 23611 parts 2, 3 and 4).

The validated methods will be submitted to ISO TC190 SC4 WG2 for preparation of new ISO standards.

Information on the study procedure

The ring test will include a test phase and a validation phase.

Test phase

Two test samples need to be processed according to the provided protocols and checked for their DNA amounts and quality:

• one soil invertebrate sample for DNA extraction and PCR
• one DNA sample of soil invertebrates for PCR

Validation phase

Six different validation samples need to be processed according to the provided protocols and checked for their DNA amounts and quality:

• three samples of artificial soil invertebrate communities, each consisting of one group of nematodes, enchytraeids, or microarthropods (two replicates each): DNA extraction of the six samples, DNA mixing and PCR
• three DNA samples (each extracted from a group of either nematodes, enchytraeids, or microarthropods): DNA mixing and PCR

All PCR reactions are to be performed using the provided primers and a recommended DNA polymerase.

Library preparation and sequencing are performed by an external company, i.e. PCR products need to be sent on dry ice to a provided address.

Participation

If your laboratory is equipped for and experienced in DNA extraction (e.g. magnetic beads or silica column-based) and PCR methods, we invite you to participate in our ring test.

Participation is free of charge, and you can register until the 30^th of October 2024.

Timeline

Test samples and validation samples will both be shipped on dry ice between 4^th and 8^th November 2024, together with instructions for processing of the test samples. However, instructions for processing of the validation samples will be provided after data evaluation of test samples by the organizers, and latest by the end of December 2024.

Deadline for submission of results for the training phase samples: 8^th of December 2024.

Analysis of the validation phase samples: 2^st January 2025 to 28^th of February 2025.

Organization and funding

Planning, organizing, sample preparation and data analysis is performed in close co-operation of Senckenberg Gesellschaft für Naturforschung, LOEWE-TBG, Fraunhofer IME, QuoData GmbH and Institut Dr. Nowak GmbH & Co. KG.

The ring test is part of the “MetaInvert” project (“Standardization of genetic methods for the characterization of soil invertebrate communities as a prerequisite for their use in soil quality assessment”), supported by the Federal Ministry for Economic Affairs and Climate Action on the basis of a decision by the German Bundestag - project no. (FKZ) 03TN0054B.