The Trypan Blue Exclusion Test is a method used to determine the viability of cells by examining their ability to exclude the dye trypan blue. Live cells, which have intact cell membranes, will not take up the dye and will appear clear under a microscope, while dead cells will be stained blue. The test involves suspending cells in PBS or serum-free medium, mixing them with trypan blue, and then counting the number of viable and nonviable cells using a hemacytometer. The percentage of viable cells is calculated based on the counts. This technique is simple and rapid but can be subjective, leading to potential errors. More sophisticated methods, such as flow cytometry, can provide more accurate and precise results but are more complex and time-consuming. Recent advancements include automated fluorescence microscopes that can rapidly and reliably count live and dead cells, making them useful for high-throughput applications.The Trypan Blue Exclusion Test is a method used to determine the viability of cells by examining their ability to exclude the dye trypan blue. Live cells, which have intact cell membranes, will not take up the dye and will appear clear under a microscope, while dead cells will be stained blue. The test involves suspending cells in PBS or serum-free medium, mixing them with trypan blue, and then counting the number of viable and nonviable cells using a hemacytometer. The percentage of viable cells is calculated based on the counts. This technique is simple and rapid but can be subjective, leading to potential errors. More sophisticated methods, such as flow cytometry, can provide more accurate and precise results but are more complex and time-consuming. Recent advancements include automated fluorescence microscopes that can rapidly and reliably count live and dead cells, making them useful for high-throughput applications.