Sample Preparation for OPTIR-FISH to Probe Glucose Metabolism in Bacterial Communities

To begin, take standardized calcium fluoride slides. Immerse them in 70%ethanol for 15 minutes, and rinse them two times with deionized water. Transfer the clean slides into 0.1%poly L lysine solution and incubate them overnight at four degrees Celsius.

Then rinse the slides with deionized water and let them dry. Next, thaw the prepared cell samples at room temperature while keeping them protected from light. To avoid excessive salt crystals from PBS during sample drying, wash the thawed cells twice with deionized water.

Centrifuge at 14, 000 G for 10 minutes, and remove the supernatant. Reintroduce the original volume of deionized water to the cells and gently vortex them. After washing centrifuge the cells at 14, 000 G for 10 minutes to concentrate the bacterial cell samples and remove the supernatant.

Gently vortex the remaining solution for approximately 30 seconds and apply one to two microliters of this solution onto the prepared calcium fluoride slide.