Diatomaceous Earth Plasmid Prep
Special instructions for slurry:
Stir in a very clean glass beaker reserved solely for this purpose. Use a magnetic stirrer
with gentle heating. Most of the guanidine HCl will dissolve in 5-10 minutes, but there will
be a fine flurry precipitate that won't dissolve.
Adjust pH to 5.5 using indicator paper and 5 M NaOH. You will need 3-4 ml of 5 M NaOH.
pH adjustment does not need to be ultra-precise.
Pour the contents of the beaker into a clean 100 ml measuring cylingder reserved
for this purpose only. The volume will be about 75-85 ml. Add milli-Q water to 100 ml,
pour back in beaker and continue to stir with gentle heat for another 5 minutes.
Weigh the diatomaceous earth into a very clean glass bottle reserved for this
purpose only.
Filter the guanidine HCl solution in the beaker through 1 layer of Whatman
filter paper using a clean filter funnel and collect the filtrate directly into the bottle
contaning the diatomaceous earth.
Shake very well to make a slurry solution, store at room temperature.
