I am currently extracting RNA from whole wheat grains at different developmental stages using a CTAB extraction buffer containing: 2% CTAB, 2% PVP, 100mM Tris-Hcl , 25mM EDTA, 2M NaCL and 0.5g Spermidine that was mixed before autoclaving.

I have used the stock solution multiple times, heating it to 65 degrees (c) before allowing it to cool to room temperature before storing at 4(c), where it tends to precipitate.

I have so far practiced extractions on surplus material but am about to start on my proper experimental material and therefore would like to know whether the buffer will be ok to use or whether I should make up some fresh. Any help appreciated