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Xenobio's avatar

When I was a young Masters student, I wondered why the price of molecular grade agarose was 500x that of grocery store agar. I tried taking some from my kitchen to the lab, boiled it in TAE (Tris, acetate, EDTA buffer) and tried running a DNA gel on it. The bands came out all wiggly and blurred. Not surprisingly, it's much less homogenous!

I'm curious as to how they separate out the different molecular weights/gel pore sizes of molecular biology grade agar. Is that inherent to what's being synthesized by the algae and dependent on species and growth conditions, or is there a separation process during manufacturing?

Corrado Nai's avatar

The chemistry is quite complex and not something I dare to venture too much into. The FAO put put quite some comprehensive reviews, though, take a look!

Sébastien Simoncelli's avatar

Also, the bit about agar being “standard” so it’s hard to replace feels painfully familiar. Even if you find a better material, you’re fighting protocols, comparability, and the inertia of decades of literature. The tech constraint isn’t just chemistry, it’s the ecosystem around it.

Fitful Musings's avatar

Excellent, captivating writing. Thank you.

Corrado Nai's avatar

Thank you!

Bill Smith's avatar

What an enlightening piece. Before reading, I only though of agar as a cooking ingredient.

Corrado Nai's avatar

Thank you! It baffles me that agar is generally not well known!

Xenobio's avatar

Especially as vegetarianism is becoming more popular in Western countries I'm surprised that it's still confined to Asian grocery stores here in the USA and not being marketed more heavily as "vegan jello"