You can use: LIVE/DEAD® BacLight™ Bacterial Viability Kit, for microscopy & quantitative assays. [ https://www.lifetechnologies.com/order/catalog/product/L7012 ]
Description:
The LIVE/DEAD BacLight Bacterial Viability Kit "for microscopy and quantitative assays* is a convenient and easy-to-use kit for monitoring the viability of bacterial populations as a function of the membrane integrity of the cell. Cells with a compromised membrane that are considered to be dead or dying will stain red, whereas cells with an intact membrane will stain green.