The Countess™ Automated Cell Counter from Invitrogen is a benchtop automated cell counter. It can perform cell counts as well as viability and cell calculations. The Countess has a touch screen display and allows data to be transferred via USB drive to a computer for data access and storage.
The Countess is very inexpensive compared to other automated cell counters. It is also portable, small, and lightweight; thereby, taking up very little bench space. The Countess is user-friendly and comes ready-to-use upon arrival. It does not need an external computer like other similar models. The Countess can measure cell concentrations from 1x104 to 1x107 cells per mL. The mean diameter of cells can be measured from 5 um to 60 um. Disposable cell counting chamber slides are necessary to use the Countess; however, as they eliminate cross contamination among various cell lines.
To use the Countess, simply combine 10 uL of trypan blue with 10 uL of cells. Mix and add 10 uL of mixture to one side of the disposable cell counting chamber slide. Insert the slide into the allotted slot on the front of the machine. The image of the cells will immediately appear on the screen. Focus the cells using the knob on the right. Press the start button to count the cells. The count normally takes less than a minute. After the cells have been counted, the data appears on the screen including total count, live count, dead count, and mean diameter. From here, you can select a separate screen, which will provide cell count calculations based on the information provided. We tested the accuracy of the Countess versus a traditional hemacytometer and found almost no difference in the cell count.
After the cells have been counted, the data can be transferred to a personal computer via USB drive. The cell images can then be viewed and saved for later access. Graphical data is also provided.
A negative feature of the Countess is that disposable counting slides must be purchased to use with the machine. Depending on the usage, this can add a substantial amount of cost to owning the Countess. Another negative feature is that only one cell counting chamber slide can be entered into the machine at once. This differs from other automated cell counters where cell samples can be put into queue and the machine will automatically accept the sample when it is ready. The many positive features of the Countess, added with its affordability and the accuracy, should out-weigh the negative features for most researchers.
Overall, the Countess automated cell counter from Invitrogen is a great addition to any lab. Because it is inexpensive and small, it can easily fit into a lab’s budget and workspace. It is also user-friendly and produces quality reproducible data.