Cell Wall Lysis For Dummies - (Apr/01/2009 )

Preface: I am a mechanical engineer with only a personal interest in biology, so please excuse my lack of understanding or misuse of terms.

My goal is to extract the contents of "spirulina" (I think chlorella) cells for use as a food colorant. I'd like to maintain the bluish emerald colors that come from the different pigments, but in my brief experimentation, boiling the sample in water appears to harm the blue pigments, and the solution becomes yellow/green. Exposing the sample to a low pH solution (H2O and citric acid) extracts a small amount of sky-blue color, and nothing else. A 20% alcohol solution seems to be retaining good color, but I think it may just be keeping the cells in suspension. I'd like to have the majority of the proteins fall out of suspension.

I've read about a freeze-thaw method, but it seems to always mention conducting the freeze-thaw cycles in some kind of buffer (pH buffer?) and with detergents.

Are there any food safe methods of breaking the cell walls that do not require highly specialized equipment or chemicals?

The spirulina is in dried powder form, and was purchased as a dietary supplement.

Thanks a lot.

Why not use a mortar and pestle or a liquidiser?

or even a sonicator if you can get your hands on one.

I don't have access to the proper tools - I do have a mortar and pestle. Would it work to freeze a soultion and then pulverize? I guess I expected that the cells would be too small for this to have much effect.

well in a lab we run here in our college we use a pestler and morter and also extract with acetone. i expext you dont have this solvent so the morter and pestle is fine, add some liquid to help such as water or any other liquid you dont think will interfere

to remove excess liquid place in a water bath or oven to evaporate

thanks for the help - is the acetone used because it evaporates easily, or does it have a special function?