TC20 Automated Cell Counter
Quick Guide
The TC20 Automated Cell Counter counts cells in one simple step,with or without trypan blue staining, and assesses cell viability via
trypan blue exclusion.
The TC20 Automated Cell Counter is designed to count suspended cells
that have been grown as adherent or suspension cells. The TC20 Counter
demonstrates high reproducibility when counting cells within the rangesof 5 × 10 4 –1 × 107 cells/ml and 6– 50 µm cell diameter.
Important: Carefully read the safety information and instrument
operating specifications provided in the TC20 Automated Cell Counter
Instruction Manual before using the system.

Fig. 1. Loading the sample onto a slide.

Preparing Samples
Important: Handle the counting slides using the edges and avoid
touching the optical surface of the slides. Counting slides cannot bereused. Dispose of used slides as biohazardous waste according to
your local environmental health and safety regulations.
Preparing Samples without Trypan Blue

Pipet 10 μl of the cell suspension into the outer opening ofeither of the two chambers of the counting slide (Figure 1).
Preparing Samples with Trypan Blue

1. C ombine 10 μl of the cell suspension with 10 μl of trypan blue.
When counting the sample in duplicate, combine 20 μl of the cellsuspension with 20 μl of trypan blue. Gently pipet up and down ten
times to mix the cells and dye.
2. W ithin 5 minutes of mixing, pipet 10 μl of the mixture into the outeropening of either of the two chambers of the counting slide (Figure 1).
Note: Trypan blue is toxic to cells and prolonged exposure canintroduce errors when attempting to determine live/dead ratios.
Performing Cell Counts
1. C ompletely insert the slide into the slide slot (Figure 2). If the slide is
not completely inserted, the instrument does not detect the slide andcounting does not start.
2. T he TC20 Cell Counter automatically detects the presence of the slideand initiates a count. The TC20 Counter also automatically detects
the presence of trypan blue.
Important: Do not remove the slide or interrupt the instrument while itis performing the count.

Fig. 2. Inserting the slide into the TC20 CellCounter; counting automatically begins.

3. For samples without trypan blue — on theCurrent count screen, the TC20 Counter provides thetotal cell count per ml.
4. For samples with trypan blue — on the Current count screen,
the TC20 Counter provides the total cell count per ml, live cellcount per ml, and percentage of live cells (Figure 3). It also
accounts for a 1:1 dilution with the dye and provides a dilution
calculation based on live cells.
Important: If the number of cells is above or below the range
detected by the instrument, a “Value out of range” message
appears on the Current count screen. Press the down arrow key
to select View image, then press Enter. View the image of thecells and determine whether the sample should be diluted orconcentrated. Repeat the cell count.

Fig. 3. Current count screen showing total cell count, live cell count, andpercentage of live cells; cell viability is measured via trypan blue exclusion.

5. O nce the instrument completes the cell count, remove the slidefrom the slide slot.
Additional Analysis Options
Additional analysis options are available in the Current countscreen. Use the up or down arrow keys and press Enter to accessthe following screens: Histogram/gating, Export image, Print count,
Dilution calculator, and View image. Helpful tips for each screen areprovided below.
Histogram/Gating

The histogram of the cell size distribution from the most recent
count shows the approximate cell diameters (μm) on the x-axis andthe cell counts on the y-axis. To modify the position of the cell size
gates, follow the instructions displayed under the histogram.
Export Image

If the automatic data export is disabled in the Autosave/sample
name menu, then the Export image option is added to additional
analysis options. Make sure the USB key is inserted in USB port A.
Print CountThe TC20 Automated Cell Counter allows you to print the cellcount using the thermal label printer (Bio-Rad Laboratories, Inc.,
catalog #1450005) connected to USB port A or USB port B on
the cell counter.
Dilution Calculator

In the Dilution calculator, the current count is used as the starting
cell concentration. The parameter that is ready to be modified ishighlighted. Press the up or down arrow key to find the correct
value, then press Enter to confirm the selection. To print the Dilution
calculator screen, press the down arrow key and select Yes.

Fig. 4. When user-defined gatesare enabled you can selectthe population of interest by
adjusting the position of the cellsize gates.
View Image

Use the up arrow key to zoom in on an image and examine
cells in detail. Use the down arrow key to zoom out.
Gating Option
While most users will let the cell counting algorithm automatically identify
cells and exclude debris, more complex samples, such as primary cells,
may require user input to identify a cell population of interest. The Gating
setup (Figure 4) is accessible from the Home screen.
Disabled User-Defined Gates

In this automatic mode, the TC20 Counter will automatically identify
cells and exclude debris, without any user input. This counting
mode is suitable for immortal cell lines or samples with little cellsize variation.
Enabled User-Defined Gates

In this user-defined mode, use the size gates on the histogram,which are displayed at the beginning of the count, to select therange of cell sizes to be counted. Select this counting mode forsamples with a wide range of cell sizes, such as primary cells.
Visit bio-rad.com/TC20 to learn more.
BIO-RAD is a trademark of Bio-Rad Laboratories, Inc. All trademarks used herein are theproperty of their respective owner. © 2024 Bio-Rad Laboratories, Inc.
For Research Use Only. Not for use in diagnostic procedures.

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