How quickly should the tabs be lifted up?
To minimize evaporation losses, lift each tab immediately after dispensing dye into its well. Lift the tab at the same moderate rate you would use to turn on a light switch.
How hard do I need to push on the tab? How far?
A light touch is all that is needed to lift the tab, until you feel it stop moving. Do not push hard, or you will risk breaking the end of the capillary. Leaving the tab up will reduce evaporation, thereby providing you more time to compare the meniscus to the adjacent markings.
Can I use my robot to lift the tab up on the Checkit Go?
Yes. You can use your robot to lift up the tab if it comes equipped with a paddle to perform this task.
How do I avoid air bubbles?
First when dispensing into the well, if you do a blowout, lift the end of the pipette tip out of the pool of dye in the well.
How do I center the dye in the well?
You can touch your pipette tip to the bottom of the well to help find the center. On the smaller volume wells, you can feel a divot at the bottom to guide the pipette tip. You can also use your pipette tip, carefully, to help guide dye to center after pipetting. If your hands are shaky, it helps to use two hands when pipetting or ask someone else for assistance.
How accurate is the Checkit?
The Checkit Pro is accurate to within 1%, aside from external influences such as evaporation. The Checkit Go is accurate to within 2%. We will likely be able to substantiate 1% accuracy once the product has enough history.
What is the cross-hatched rectangle on the Checkit Pro?
ISO 8655 standard covers the accuracy requirements of hand held, single channel, adjustable pipettes. The rectangle illustrates the acceptable range. Note that the width of the ISO rectangles does not factor in the 1% accuracy of the pipette Checkit®.
Can the Checkits be used to test someone’s pipetting technique?
Yes, one good application of the Checkits is testing the accuracy of a person’s pipetting technique.
Can the Checkits be re-used?
No, the Checkits are designed to be disposable.
Can I replace the glass capillaries?
No. To ensure accurate readings, the capillaries are precisely positioned to within .001 to .002 inches (25 to 50 micrometers). It would be near impossible to refill the Checkit with such accuracy.
In what order should I test my pipette at the high, middle, and low end of its range?
We suggest that you test the high end of the range first, then the middle, and finally the low end. For example, with a 20uL Checkit, first test it for 20 uL, then for 10 uL, and finally for 2uL.
Can I use the Checkit outdoors?
For accurate readings, the Checkit must be on a level surface, near room temperature. It will not be affected by altitude, humidity, or small changes in temperature.
Is the Checkit’s performance affected by changes in temperature?
Temperature should not have a significant effect on the Checkit between 4-40°C and its readings change less than 0.07% with a 10°C change. The evaporation effects are minimal once the droplet is in the glass capillaries in the Checkit. Thus making it more accurate than a scale. While the density of the water changes (and so the observed mass for a given volume) between 4-40°C, the glass capillaries are not subject to much thermal expansion over this range. Therefore, the volume should stay very close to accurate between these temperatures. Since the Checkit measures pipette volume with volume, there is no conversion of units like with a scale (from mg -> mL). Given the volume on the Checkit is read in the same experimental environment of your pipette, it is a more accurate reflection of how your pipette performs. This is an advantage of the Checkit over classical methods.
How level does the work surface have to be?
The Checkits work on any reasonably level surface. The glass capillaries are mounted at a slight incline to ensure that capillary action draws all the dye into the capillary, slightly uphill, against gravity.
How do I dispose of the dye?
The dye is safe and non-toxic. It can be disposed down a sink drain.
Is Checkit Go compatible with solutions containing 2% SDS or other surfactants?
Surfactants can interfere with the operation of Checkit. Find a list of solutions that are compatible on the Features page.