Home Cell Biology CCK-8 Operation Guide & Data Analysis
Steps
  1. 1 Prepare and centrifuge cultured cells 00:16
  2. 2 Count cells and adjust concentration 00:41
  3. 3 Set up experimental plate and controls 01:31
  4. 4 Treat cells and incubate 01:59
  5. 5 Add CCK-8 reagent and incubate 02:49
  6. 6 Measure optical density values 03:29
  7. 7 Calculate and analyze data 03:55
Cell Biology YouTube (Curated Tutorials)

CCK-8 Operation Guide & Data Analysis

Protocol
Difficulty
intermediate

Steps

1
Prepare and centrifuge cultured cells

Collect cultured cells and centrifuge at 300× gravity for 5 minutes to pellet the cells. Discard the supernatant.

▶ 00:16
2
Count cells and adjust concentration

Resuspend cells in fresh calcium medium and count them using a microscope. Adjust the cell concentration as needed.

▶ 00:41
3
Set up experimental plate and controls

Prepare the 96-well plate by adding 100 µL PBS to blank wells, 100 µL calcium medium to negative control wells, and 100 µL cell suspension to experimental wells according to the experimental design.

▶ 01:31
4
Treat cells and incubate

Apply experimental treatments to the cells according to the experimental protocol and incubate in a cell incubator.

▶ 01:59
5
Add CCK-8 reagent and incubate

Add 10 µL of CCK-8 buffer to each well and incubate the plate to allow the color reaction to develop.

▶ 02:49
6
Measure optical density values

Measure the optical density (OD) value of each well at 450 nanometers using a microplate reader.

▶ 03:29
7
Calculate and analyze data

Organize data by group and calculate average OD values. Subtract the blank group average from each group, then divide by the negative control value minus blank to determine the cell viability rate.

▶ 03:55

🚨 Failure Case Library (5) + Submit your own case

severe
OD values are too low — close to background
Most OD values are below 0.1, the curve is essentially flat along the x-axis, and group differences are invisible.
💡 5 · ✓ 5
severe
OD values are too high — beyond detection range
OD450 readings approach or exceed 3.0, the curve hits its upper limit, and treatment vs control look indistinguishable.
💡 5 · ✓ 5
severe
High background — control OD is abnormally elevated
Even blank wells (medium + CCK-8, no cells) show high OD; control group reads abnormally high.
💡 5 · ✓ 5
moderate
High well-to-well variability — poor reproducibility
Parallel wells in the same group give widely different OD values; SD bars are very large.
💡 5 · ✓ 5
moderate
Group differences are too small to distinguish
Treatment and control curves are nearly overlapping, error bars overlap, no statistical significance.
💡 5 · ✓ 5
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