Procept® - Eichrom

Some test components are stored in freezers (-20 o C and -80 o C). Care should be taken to avoid
direct contact of frozen components with skin.
H. Pipetting Tips
Table 2. Cross-Reactivity on the Procept ® Assay
Procept® Assay
Congener WHO 2005 TEF response factor
2,3,7,8 TCDD 1 1
1,2,3,7,8 PCDD 1 0.6
2,3,4,7,8 PCDF 0.3 0.3
1,2,3,7,8,9 HxCDD 0.1 0.5
1,2,3,4,7,8 HxCDF 0.1 0.4
1,2,3,4,7,8 HxCDD 0.1 0.4
1,2,3,7,8,9 HxCDF 0.1 0.3
1,2,3,6,7,8 HxCDF 0.1 0.2
1,2,3,6,7,8 HxCDD 0.1 0.1
2,3,4,6,7,8 HxCDF 0.1 0.1
2,3,7,8 TCDF 0.1 0.06
1,2,3,7,8 PCDF 0.03 0.1
1,2,3,4,6,7,8 HpCDD 0.01 0.01
1,2,3,4,6,7,8 HpCDF 0.01 0.05
1,2,3,4,7,8,9 HpCDF 0.01 0.02
1,2,3,4,6,7,8,9 OCDD 0.0003 0.000003
1,2,3,4,6,7,8,9 OCDF 0.0003 0.0005
The precision and accuracy of the Procept ® Rapid Dioxin assay can be affected by the pipetting
technique of the user. Below are several pipetting tips for achieving the best possible results with the
Procept ® Rapid Dioxin Assay.
-Be consistent. Have a pipetting routine and keep the routine consistent throughout the samples in
a single assay and between multiple runs of the assay.
-When pipetting solvents with a higher vapor pressure than water (i.e. heptane or hexane), practice
positive displacement pipetting. Draw the solvent into the pipet tip and dispense to the first stop on
the dispensing mechanism (do not depress the dispensing mechanism to the second stop) to prime
the pipettor. Repeat this procedure 2-3 times, then, draw the solvent into the pipette tip a final time
and dispense the solvent into the desired container by depressing to the first stop of the dispensing
mechanism. A small amount of solvent may remain in the pipette tip, but an accurately measured
amount of the solvent will have been dispensed.
-Use a fresh pipette tip for each sample/standard during the assay and for each dilution when
preparing the 2,3,7,8-TCDD standards. This will minimize the possibility of cross-contamination
between samples or standards.
-Use the lid from the box of pipette tips and the pipette tips themselves to keep track of your
position on the 96-well plate. When using a full test kit, it can be difficult to keep track of where each
sample or standard should be added on the 96-well plate. The lid of the pipette tip box can be used
to keep track of the column to which each sample or standard should be added. As the user
progresses through the test and reaches the end of a column, the lid can be moved to the next
column of the 96-well plate. Additionally, the pipette tips are organized in the same format as the
96-well plate. By using a fresh pipette tip for each sample/standard and removing the pipet tips in
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