A framework for optimising arthropod DNA quality and quantity for modern sequencing tools using hard ticks (Ixodidae)

Advanced sequencing technologies require strict standards for DNA input and integrity. This study addresses the challenge of extracting high-quality, endogenous DNA from smaller arthropods with mixed DNA sources (arthropod, host, and microbiome), using Amblyomma triguttatum as a model organism. We evaluated three tissue types (Whole, Bisected, and Legs), three disruption methods (Undisrupted, Sliced, and liquid nitrogen bead Homogenisation), and two extraction kits (Qiagen DNeasy Blood & Tissue and MagAttract HMW) to optimise DNA yield, quality, and composition. The Qiagen MagAttract High Molecular Weight Kit significantly increased the proportion of large DNA fragments (20-48.5 kbp) by 11-fold compared to the Qiagen DNeasy Blood & Tissue Kit. Aggressive homogenisation methods produced the highest proportion of short fragments (97%, 1-10 kbp). Whole-Homogenised specimens yielded the highest DNA concentration (198 ng µL⁻¹), whereas Bisected-Undisrupted specimens achieved 146 ng µL⁻¹ with a greater proportion of large fragments (3.15%). Bacterial DNA content remained consistent across treatments. Our findings highlight the importance of selecting appropriate extraction methods to ensure optimal DNA quality for advanced sequencing applications. These results provide useful guidelines for optimising DNA extractions from smaller-bodied arthropods (~ 10-20 mg) and establish a framework for future studies to consider DNA quantity, quality, and composition.