Countess
™
II Automated Cell Counter User Guide
15
3. Cell count and cell viability assays
Prepare sample
Recommendations
To obtain the best results, follow these recommendations:
•
Ensure that the cell sample is homogeneously mixed.
•
The measurement range extends from 1 × 10
4
–1 × 10
7
cells/mL, but the optimal
range is 1 × 10
5
–4 × 10
6
cells/mL.
•
For accurate results in cell viability assays, ensure that the counting area is
covered with the cell suspension and count the cells immediately after staining
per the assay protocol.
•
Do
not
press the optical surfaces of the chamber slides. Hold the slides by the
edges.
•
Take care to avoid forming bubbles in the sample.
Load Countess
™
Chamber Slide
1.
Prepare the sample by adding 10 μL of your cell suspension to 10 μL of 0.4%
trypan blue stain. Mix the sample mixture well by pipetting up and down a
few times.
2.
Gently pipet 10 µL of the trypan blue-stained sample into the half moon-shaped
sample loading area. The sample is loaded into the chamber through capillary
action.
Note:
Each chamber in the Countess
™
Cell Counting Chamber Slide has a
10-µL sample capacity. Do not overfill the slide chambers.
3.
Let the sample mixture settle in the chamber for 30 seconds, and then insert the
slide into the slide port (see page 8). You will hear a soft click, if the slide is
pushed in correctly.
4.
To remove the slide, push the slide gently into the instrument until it "clicks"
and a spring pushes the slide out. Grasp the slide and pull it out the rest of the
way.
Note:
After using the Countess
™
Cell Counting Chamber Slides,
appropriately dispose of them as biohazardous waste. Do
not
reuse the
disposable chamber slides.