Cell Counting 101 – What is Manual Cell Counting? – Choosing the Best Method For You

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– 4 min read

During the last couple of months, we’ve written blog posts that cover everything you need to know about manual cell counting. If you think we’ve missed anything, feel free to leave a comment below and we’ll cover your topic in a future post.

Counting Cells Using a Hemocytometer

The hemocytometer is an important tool for manual cell counting. You load a sample into it, look at the cells through a microscope and count them using the etched grid. You often need to dilute the sample for a manageable cell count. It’s important to keep track of the dilution factor since you will need it for later calculations.

The final cell count is used to determine factors like the total cell count, cell viability and variance. You can also calculate the standard deviation between different cell counts to validate the precision of your cell counts overall.

As with any other type of experiment, data validation is important when performing cell counts. This especially applies if you are counting manually because this method is associated with an error range of up to 20 – 30%1, which suggests that your results have room to improve in accuracy.

Eliminate Errors

If you want to minimize your cell counting errors, consistency is king. Make sure that you prepare dilutions correctly, are careful when pipetting, set clear guidelines to follow when you count and be diligent about what you count as a cell.

In this Mini Review, we have included a section on how you can test your cell counting skills. Here is a blog post about how you can validate your cell count, which you might find useful. Alternatively, watch the webinar on the same topic by Annemieke Karyotis, one of our FAS in the UK.

As another option, you can explore the automated cell counting method. Here, you eliminate errors because it’s a fully automated process which ensures consistency in the counting protocol every time. You also minimize calculating errors because the automated cell counter is pre-set to perform the calculations. See how you can get half the variance in your cell counts compared to when you use a hemocytometer for manual cell counting2 with the NucleoCounter® NC-202™ automated cell counter.

Further Reading


  1. Electron Microscopy Sciences: Neubauer Haemocytometry
  2. Chemometec: Tech Note: NucleoCounter® NC-202™ Performance Data

By Christina Psaradaki, Student Assistant at ChemoMetec
Christina Psaradaki studies Human Life Science Engineering at the Technical University of Denmark. At ChemoMetec, she writes for the Cell Counting Blog.


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