Page 4 - LabconProtectR.pdf
P. 4

  Protect samples from acidification
Other container closure systems do not provide a reliable barrier against CO2 sublimating from dry ice. Carbonic acid formation will cause a decrease in pH by as much as 2.5 pH units. In this experiment, acidification is seen as a solution's color shift from blue to yellow.
  Acidic Neutral Alkaline
4.0 6.0 7.0 8.0 9.0 10.0
     Other Tube 1
Drop in pH
ProtectR® Tubes
No change in pH
Other Tube 2
Drop in pH
    Measuring Sample pH Changes
pH changes seen as color shift from blue to yellow
Control
pH 8
Dry Ice
Upon thawing after dry ice exposure
ProtectR® Tube
No change in sample pH
Other Tubes
Change in sample pH
          CO2 Intrusion Test:
Other Tubes vs. Labcon ProtectR® Tubes in preventing pH change of sample
Other Tubes vs. Labcon ProtectR® Tubes
           80% Fill
40% Fill
20% Fill
80% Fill
40% Fill
20% Fill
                CONTROL
DRY ICE
(CO2)
CONTROL
DRY ICE
(CO2)
CONTROL
DRY ICE
(CO2)
CONTROL
DRY ICE
(CO2)
CONTROL
DRY ICE
(CO2)
CONTROL
DRY ICE
(CO2)
             Sample pH
8.05
6.06
8.02
5.53
7.99
5.50
8.1
8.09
8.05
8.02
8.00
7.95
                pH Change
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          EXPERIMENT:
Pre-Frozen* tubes of buffered pH 8.0 solution were placed on dry ice for 48 hours.
RESULTS:
Carbon dioxide enters Other Tubes headspace and acidification expands through the protein solution.
*Samples in ProtectR® Tubes should be frozen prior to dry ice exposure.
FINDINGS:
Only the ProtectR Tube protected the solution from acidification.
CONTROL
DRY ICE
CONTROL
DRY ICE
DRY ICE
CONTROL



















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