Bio-Rad PureZOL™ RNA Isolation Reagent User Manual
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recommended to disrupt the cell walls of yeast and bacteria.
Bacteria and yeast lysate can also be heated to 55°C for 10
minutes prior to adding chloroform to increase the effectiveness
of lysis by PureZOL. Note: Do not wash cells prior to the
addition of PureZOL as this could increase the possibility of
mRNA degradation.
Fresh Tissue
Freshly harvested tissue samples should be processed
immediately after dissection to avoid RNA degradation.
Alternatively, the tissue can be immediately frozen in liquid
nitrogen and processed using instructions for frozen tissue.
To process a freshly dissected tissue, add 1 ml of PureZOL for
every 50–100 mg of tissue in a suitable sized tube for disruption
and homogenization, and homogenize the sample for
30–60 seconds using a rotor-stator or bead mill homogenizer
(refer to manufacturer’s instructions for details). Although not as
effective, passing the tissue sample through an 18-gauge needle
and syringe can be used for sample disruption if a homogenizer
is not available. Pass the sample through the needle and
syringe until no more solid tissue is left in the lysate. The
sample volume should not exceed 10% of the volume of
PureZOL used for disruption.
Frozen Tissue
Grind the frozen tissues to a fine powder with a mortar and
pestle under liquid nitrogen. Avoid thawing the sample, by
periodically adding liquid nitrogen to the mortar. Weigh up to
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