The days are starting to get longer here in Brazil as we get closer to primavera—but of course I’ll be heading back soon to the northern hemisphere, just in time to catch a little bit of summer up there!
In the lab, I’ve finished up the cell wall fractionation protocol and will have results very soon. After washing my samples with the series of reagents described in my last post, I had to remove the salt from all the supernatant samples I collected. To do this, I transferred the samples into bags made with dialysis tubing, then moved these bags into buckets and buckets of fresh water every couple hours, up to five times per day. Via osmosis the salts passed out of the bags through the dialysis tubing, moving down their concentration gradients—while all the sugars (which are what I want to analyze) stayed inside the bags, unable to pass through the dialysis tubing. With my seventy samples, this took a while to complete. But now all salt has been removed and my samples are currently in the freeze-drying machine (we can’t dry the samples in the oven like usual at this step, because some of the sugars are too volatile).
Next I’ll perform acid hydrolysis again (see my last post) with all of these samples to break down the polysaccharides into monosaccharides, then analyze these monosaccharides using HPLC. Then we’ll finally have something to say about the cell wall architecture of these corn samples!