LG10_DEEP: Deep soil sample (DEEP) collected by extracting 20 L of soil to a depth of approximately 25-30 cm (A and B horizons) after removal of the superficial soil layer (SUP), and processed using flotation and Berlese extraction.
A 418 bp fragment from the 3' end of the mitochondrial COI barcode region (bc3') was amplified using primers Ill-B-F and Fol-degen-R with Illumina adapter tails. Three independent PCR reactions were performed per sample and pooled. Amplicons were purified using AMPure XP magnetic beads and used as template for a limited-cycle PCR to incorporate dual-index barcodes and Illumina sequencing adapters.