FN Archimer Export Format PT J TI A new protocol using acidification for preserving DMSP in macroalgae and comparison with existing protocols BT AF Bucciarelli, Eva STIGER-POUVREAU, Valerie Connan, Solène AS 1:1;2:1;3:1; FF 1:;2:;3:; C1 Univ Brest CNRS IRD, Ifremer, LEMAR F‐29280 Plouzane, France C2 UBO, FRANCE UM LEMAR IN WOS Cotutelle UMR IF 3.173 TC 2 UR https://archimer.ifremer.fr/doc/00663/77503/79241.pdf LA English DT Article DE ;acidification;DMSP;drying;freezing;macroalgae;storage protocol AB Dimethylsulfoniopropionate (DMSP) plays many important physiological and ecological roles in macroalgae. The most common method to measure DMSP is by gas chromatography analysis of the dimethylsulfide (DMS) produced after NaOH hydrolysis (pH > 12). Storage of DMS, however, is not recommended for more than a week. We investigated if acidification can be a suitable method to preserve DMSP in macroalgal samples over three months of storage, compared to widely used protocols such as drying and freezing at ‐20°C. The DMSP content of green (Ulva sp. and Ulva compressa), red (Chondrus crispus) and brown (Bifurcaria bifurcata) macroalgae were analyzed 24 h after NaOH addition (control values); and after acidification (0.2 mol · L HCl‐1) for 24 h of fresh material, followed by NaOH addition for 24 h. These values were compared to measurements after 3‐month storage of samples that had been either dried in a heater (60°C for a night, and storage at room temperature), or frozen at ‐20°C, or kept in 0.2 mol · L HCl‐1. There was no significant difference between DMSP measurements on freshly collected material and after acidification of the samples, whether 24 h later or after 3 months of storage. This was in contrast with 3‐month storage protocols involving overnight drying at 60°C (75‐98% DMSP loss), and to a lesser degree freezing at ‐20°C (37‐80% DMSP loss). We thus advise to acidify macroalgal samples for preservation over long periods of time rather than drying or freezing, when assaying DMSP content. PY 2021 PD APR SO Journal Of Phycology SN 0022-3646 PU Wiley VL 57 IS 2 UT 000614643900001 BP 689 EP 693 DI 10.1111/jpy.13113 ID 77503 ER EF