There are over 1.6 million species of animals and 435 thousand species of plants on Earth. Long-read sequencing technology is enabling biologists to digitally archive the genomes of these organisms to understand fundamental basic questions in evolution, boolster conservation strategies in the midst of massive extinctions, and improve food production through crop and livestock genomics. One of the primary challenges however, is obtaining samples from field sites and preserving them in a way that ensures high quality DNA for long read sequencing. Here we demonstrate the impacts of storage time (0 days, 2 days, 7 days, 21 days, and 42 days), storage temperature (4 Celcius , 22 Celcius ), and storage buffers (95% EtOH, RNAlater , EDTA) on the preservation of fish blood across multiple species of fish. We extracted DNA using the Monarch HMW kit. DNA yield was consistently high between 10-100 ug and pure (260/280, 260/230) across most time points for the RNAlater and 95% EtOH buffers while most EDTA only samples failed after a week. Fragment lengths based on TapeStation and FEMTO pulse were highest for 95% EtOH stored at 4C even out to 6 weeks whereas for room temperature, RNAlater
faired better up to 3 weeks. We show that high quality DNA as measured by yield, purity, and fragment size can be obtained from samples stored at 95% EtOH at 4 Celcius for up to 6 weeks and RNAlater at room temperature for up to 3 weeks. We compare these storage impacts on sequencing read length, genome assembly quality, and methylation variation. For jack mackerel, our sequencing read length N50 on the Promethion was the following: gold standard control ‘snap frozen’ (37 kb, 33.2; LSK110, LSK112), 2 days at 4C in 95% EtOH (31kb; LSK110), 3 weeks at 4C in 95% EtOH (38.9 kb, 24.4 kb; LSK110, LSK112), 6 weeks at 4C in 95% EtOH (30 kb, 25 kb; LSK110, LSK112), and 3 weeks at 22C in RNAlater (18.4 kb, 11 kb; LSK110, LSK112). The LSK112 kit read lengths were 30% (mean, SD 11.5%) lower than LSK110 but with an increase in quality. Assembly results were also comparable across time treatments (for 95% EtOH at 4C) when controlling for coverage. The overall read lengths were high for all of the 95% EtOH samples regardless of storage time suggesting this as an appropriate storage mechanism for field sampling. For room temperature, RNAlater also did modestly well for up to 3 weeks. We compare our sequencing results to 10 other species of fishes sequenced using the gold standard ‘snap frozen’ method and demonstrate the feasibility of using this new storage method.