1. What is the purpose for using negative staining? 2. Nigrosin is the stain that will be used for this technique. What is its structural formula? What is the net charge of nigrosin? 3. Briefly describe how a smear is made for negative staining. 4. Why do bacteria remain unstained during negative staining? 5. What is the purpose for making a smear during negative staining? 6. What could happen if too little nigrosin is used in the preparation of a negative stain? 7. What does it mean to heat fix the bacteria? 8. What are bacteria not heat fixed prior to negative staining? 9. How would bacteria look if they were stained with safranin, a basic red dye? 1 10. Mycoplasma is a genus of bacteria that do not have a cell wall. Would the nigrosin penetrate the bacteria? Why or why not? [] m