Determination of Cell Aggregation in Bacteria Cultures for Contact Lens Disinfection Efficacy Testing
The percentage of aggregates in bacteria cultures may be determined by employing the Coulter Principle, also known as Electrical Sensing Zone (ESZ) technique. The ISO International Standard 13319 describes this technique. A suitable electrolyte solution is required to perform the analysis, in many cases the Phosphate Buffered Saline (PBS) solution used to suspend the cells may be used as the electrolyte. The sample is prepared and then analyzed using a Beckman Coulter Multisizer 3 to determine the size distribution of the cells. The results are reported as number percent of aggregates.