Yeast cells are a popular choice in biologics for the manufacture of cell products.  Yeast cells as "cell factories" have numerous advantages including their fast growth; the ability to easily manipulate their genetics and their compatibility with high-density large-scale fermentation processes for biochemical production. A reliable cell count and cell viability are crucial metrics for many regulatory aspects of biomanufacturing:

• Safety, efficacy, purity, potency, identity, quality

• Oversight of both product and process

• Quality control of source materials, intermediates, and product

• Reproducibility of lots

• Comparability after manufacturing change