Monitoring of yeast viability during the fermentation process is an important quality control procedure employed by the brewing industry. Consistent yeast viability during the fermentation process is critical for batch-to-batch consistency and overall product quality. The Cellometer Auto X4 (10x) Fluorescent Cell Counter is specifically optimized for simple, 1-step determination of yeast concentration and viability and is ideal for both small and large breweries looking to automate their fermentation monitoring. Performance of the Cellometer Auto X4 (10x) has been proven in the largest breweries in the U.S.

Application: Concentration and viability

Cell Type: Muntons Ale Yeast

Staining Method: Propidium Iodide (PI)

Assay: Propidium Iodide Viability

Instrument: Cellometer Auto X4 (10x)

Procedure

  1. Combine 20µl of yeast sample and 20µl of PI dye and mix well by pipetting up and down
  2. Load 20µl of sample into the disposable counting chamber
  3. Insert counting chamber into the Auto X4
  4. Enter Sample ID and dilution factor
  5. Display image and click count
  6. Obtain results in less than 60 seconds
  7. Data Output: Cell count, cell concentration, % viability

Muntons Ale Yeast Results

Muntons Ale Yeast bright field image

Muntons Ale Yeast: bright field image

Muntons Ale Yeast: Fluorescent image showing dead cells

Muntons Ale Yeast: Fluorescent image showing dead cells
Cell Concentration: 2.41 x 10>7
Mean Cell Diameter: 4.2 microns
Percent Viability: 81.5%
The Auto X4 is ideal for yeast viability monitoring in most beer and wine fermentation processes. Total cells are counted in the brightfield channel and dead cells are identified and counted in the fluorescent channel. With the proprietary cellometer software, chain-forming yeast and budding yeast can be accurately counted. For specialized brewers working with “messy” yeast samples containing debris, Nexcelom offers the Cellometer Vision (10x). The Vision offers a dual-fluorescence (AO/PI) method whereby live yeast cells are identified and counted in the green channel, dead yeast cells are counted in the red channel, and debris does not fluoresce. The AO/PI Yeast Viability Kit is specifically designed for analysis of yeast fermentation in samples containing debris.