Add 28.5 ml glacial acetic acid, mix and titrate with about 1.5 ml of concentrated HCl to pH 4.8. Top up to 100 ml with MQ water . It is not necessary for guanidine hydrochloride to be dissolved in TE buffer as described in Hansen et al. 6 M is preferable. Anything less than 3 M gives poor results.
Ethanol is generally good as a washing solution, except that isopropanol is cheaper.
Tris-HCl, pH 8.5, containing 1 mM EDTA 7. The preparation of this solution is crucial. Carefully discard as much of the water containing the white gelatinous colloidal suspension as possible, but leave the sediment intact. If fine gelatinous matter is found during use, then discard the supernatant carefully and replace it with the same amount of water to maintain the same concentration of diatomaceous earth as above. Again, any milky suspension of diatomaceous earth should be removed as above.