PREVI Color Gram does the tedious work for you so you are free to perform more important tasks. PREVI Color Gram is an automated gram stainer system for all types of specimens which provides accurate, standardized results. It provides standardized coloration with it's innovative spray nozzles that always dispense the same reagent volume. It eliminates cross contamination by keeping each slide separated and using fresh staining reagent each time. Features improved microorganism differentiation in comparison with manual and bath staining results.