VP-ITC MicroCalorimeter User’s Manual
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CAUTION-Contrad-70 is highly caustic and a severe eye irritant; use latex gloves and
safety glasses; make sure the cells are at room temperature or below before adding or
removing Contrad-70; follow the manufacturer’s instructions on the container.
Cool the cells to room temperature then remove and dispose of the Contrad-70. A thorough rinse
with distilled or deionized water should follow.
We do not recommend drying the cell before filling with your sample solution, but it should be
rinsed twice with the buffer you are using for the experiment. Finally, it should be completely
drained and filled with your sample solution in the manner described earlier.
A small amount of the buffer used for final rinsing will adhere to the walls of the cell and act to
dilute your sample solution, if you measured the concentration before the sample was introduced
into the cell, you may wish to correct for this by lowering your sample concentration by 2%.
Vigorous ITC Cell Cleaning Method
Occasionally, calorimeter cells will require a more vigorous cleaning method to provide
maximum sensitivity and high performance.
When the cells are at room temperature or below, fill the cells with a 10% solution of Contrad-70,
raise the temperature to 65
°
C and let stand for one hour.
CAUTION-Contrad-70 is highly
caustic and a severe eye irritant; use latex gloves and safety glasses; make sure the cells are
at room temperature or below before adding or removing Contrad-70; follow the
manufacturer’s instructions on the container.
Cool the cells to room temperature then remove
and dispose of the Contrad-70. A thorough rinse with distilled water should follow.
Cleaning Recommendations
As a general rule, the simplest effective method of cleaning is generally preferred. Short of a
very aggressive method it is impossible to give a global recommendation for all samples.
Therefore the following suggests simple to the more aggressive methods. Please note this list is
not all inclusive and many variations exist.
The selection of a cleaning agent is crucial. All of the components of the sample to be cleaned
need to be soluble in your cleaning solution. The cells of the VP ITC are constructed of a
Hastelloy
®
alloy. This alloy is highly resistant to basic solutions and partially resistant to acidic
solutions. With this in mind it is generally best to use a basic or neutral cleaning solution on a
regular basis and revert to an acidic solution only when absolutely necessary and only under
MicroCal’s specific recommendation.
Buffer Rinse:
The cell(s) are rinsed three or more times with the full volume of a filling syringe
containing buffer Generally each syringe full is repeatedly oscillated in and out of the cell before
being discarded. If more experimentation will be conducted with the same buffer, then the cell is
simply drained from the bottom and a new sample introduced. When a new buffer is to be used,
the cell is rinsed with water and drained, and the cell rinsed with the new buffer.
Detergent Rinse:
The cell(s) are rinsed three or more times with the full volume of a filling
syringe containing a detergent . A good general purpose cleaner is a 10% to 25% V/V aqueous
Top Job™ solution at
≥
50
°
C (use plastic syringes when working with hot solutions as glass
syringes may fracture). The temperature is important as the effectiveness drops greatly as the
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