Life, death, and in-between: meanings and methods in microbiology

Area of Science:

• Microbiology
• Cell Biology
• Environmental Science

Background:

• The plate count method is a standard for microbial viability determination in laboratories.
• This technique has recognized limitations, particularly for analyzing environmental microorganisms.
• Numerous alternative methods, including viability staining combined with image analysis or flow cytometry, have been developed.

Purpose of the Study:

• To clarify the definition of microbial viability.
• To provide guidance on selecting and interpreting various microbial viability testing methods.
• To address the confusion arising from the wide array of available techniques.

Main Methods:

• Review of existing literature on microbial viability determination methods.
• Exploration of the principles behind viability staining techniques.
• Discussion of complementary methods like image analysis and flow cytometry.

Main Results:

• Plate count limitations necessitate alternative approaches for microbial viability assessment.
• Viability staining, often coupled with advanced techniques, offers potential solutions.
• Commercial kits exist but may require organism-specific or instrument-specific adaptations.

Conclusions:

• Accurate microbial viability determination is crucial but challenging.
• Understanding the nuances of different viability testing methods is essential for researchers.
• This review aims to assist in the informed selection and interpretation of microbial viability assays.