Dear Carolina Vasco Costa Delgado this is a very interesting technical question. To the best of my knowledge all commonly used methods for extracting alginates from brown seaweed employ a formaldehyde treatment step. When you say that you are "working without special safety facilities" does this mean that you don't have a fume hood available at your lab? If you do have a fume hood, then working with aqueous formaldehyde solution should present no major problems. Just work in the well-ventilated fume hood and wear protective gloves in order to avoid contact with your skin. Otherwise I strongly suggest that you ask a chemist at your institution if you can carry out your experiments in a chemical laboratory. When doing such experiments it is important to learn how to safely handle toxic reagents such as formaldehyde solution.

Good luck with your work!

Dear Frank Edelmann,

Thank you for your reply!

The Open WebLab at Waag, Amsterdam, does not work with that level of security. As they are a "laboratory for biodesign, bioart and do-it-together biology", therefore there are limitations on chemicals for safety reasons. I could make it at The Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP), University of Porto, but for a sustainable and open-access approach, as for educative in Design, the methodology should consider these limitations - cleaner processes without hazard chemicals.

Best regards,

Carolina

Dear Carolina,

many thanks for your kind response and explanation. I fully understand that it would be a great advantage to avoid the use of toxic formaldehyde in this process. I just came across a very interesting review article about the topic. Perhaps this paper will provide you with some hints about alternative protocols. Please have a look at this article:

Methods of extraction, physicochemical properties of alginates and their applications in biomedical field – a review

Article Methods of extraction, physicochemical properties of alginat...

Fortunately this paper has been posted by the authors as public full text on RG. Thus you can freely download it as pdf file. It is mentioned here that pre-treatment of the algae with formaldehyde/formalin is carried out in order to soften the seaweed tissue, bleaching the algal biomass and avoid alginate pigmentation. If this is less important for your purposes, you can perhaps just leave out this step.

Good luck with your work and best wishes!

Dear Frank Edelmann,

Thank you for sharing. Indeed! I read the paper and understand that for my purpose, I can jump over this step! If it was for the commercial and scale-up process, maybe it would be relevant to find the alternative. Considering that the Sargassum muticum (invasive seaweed used for the study) is already low in alginates, my expectations on Alginate extractions are already limited.

Therefore, I'm happy that we achieved this conclusion.

Once more, thank you!

Best regards

Carolina