Brightfield cell counting simplified

The Invitrogen Countess 3 Automated Cell Counter was developed using an advanced machine-learning image analysis algorithm to deliver accurate cell counts and viability measurements in fewer than 30 seconds. The Countess 3 instrument has automated lighting, focus, capturing, counting, and saving; all you need to do is insert the slide containing a cell sample.


Choose between the disposable Countess Cell Counting Chamber Slide for maximum convenience or the Countess Reusable Slide for sustainability and cost reduction. Enjoy the speed and convenience of automation with superior counting performance.

Countess 3 Automated Cell Counter Features

The Countess 3 instrument shares common features with the Countess 3 FL model: It is accurate, precise, fast, simple, and automated; it offers viability measurement and single-cell data; it is compatible with reusable slides; and it has optional software to support 21 CFR Part 11 compliance for electronic records.

Viability measurement using trypan blue

Murine PBMCs, often difficult to count due to their small size and low contrast, were counted with the Countess 3 Automated Cell Counter. In this brightfield count, 0.4% trypan blue stain was used to distinguish viability, with live cells remaining translucent and dead cells staining dark. Red contours (circles) indicate cells counted as dead, while green contours indicate cells counted as live. 

Simple steps for automated cell counting

Videos and demos

Cell counter specifications


Technical specifications Processing time: <30 seconds
Sample concentration range: 1 x 10⁴–1 x 10⁷ cells/mL
Particle diameter range: ~4–60 µm
Cell diameter range: ~4–60 µm
Required sample volume: 10 μL
USB drive: 32 GB (FAT32-, exFAT-, or NTSF-compatible)
Optics: 5 megapixel camera, 2.5X optical magnification
Physical characteristics Instrument dimensions:
9" (W) x 5½" (D) x 9" (H); 228.6 mm (W) X 139.7 mm (D) x 228.6 mm (H)
Weight: 8 lbs; 17.6 kg
Counting area

Area: 2.26 mm x 1.69 mm (3.82 mm²)

Graphic image depicting the area of a typical standard hemocytometer and the area counted by the Countess 3 Cell counter which is significantly larger

Included with instrument USB drive for storing and transferring data to your computer
Countess Disposable Slide Holder
Countess Reusable Slide Holder
Countess Cell Counting Chamber Slides (Qty 50)
Power cord and 4 plug adaptors to accommodate most countries
Quick reference card (QRC)
Sold separately Countess Reusable Slide
High-Power USB Wi-Fi Module (dongle)
Countess Cell Counting Chamber Slides
Trypan Blue Stain
Countess SAE Software Solution
Countess 3 Cell Counting Standard Slide

Ordering information

* Extended waranty included without additional cost

For Research Use Only. Not for use in diagnostic procedures.