Stain Protocols-BIOL 2420 Simple Stain Simple stains provide a quick and easy way to determine cell shape,size,and arrangement. 1.Perform a bacterial smear,as discussed in Figure 3-52 on page 150 of your lab manual. 2.Saturate the smear with basic dye for approximately 1 minute.You may use crystal violet safranin,or methylene blue. 3.Rinse the slide gently with water. 4.Carefully blot dry with bibulous paper 5.Observe the slide under the microscope,using proper microscope technique. Negative Stain anism'scelular morphology.Since the in any way. mMis the uns ed c 1.Place a single drop of nigrosin on a clean microscope slide,adjacent to the frosted edge 2.Usinga flamed loop and steri i remove some organism from yo and mix it into the dr rop of nigrosin. Be ue there are no large clumps of organism,but try to avoid spreading the drop. 3.Place the end of another clean microscope slide at an angle to the end of the slide containing the organism and spread the drop out into a film.This is done by contacting the drop of nigro slide and using the capillary action of the s the s 4.Allow the film to air dry. 5.Observe the slide under the microscope,using proper microscope technique. Smith-2010 Page1of4Stain Protocols – BIOL 2420 Smith – 2010 Page 1 of 4 Simple Stain Simple stains provide a quick and easy way to determine cell shape, size, and arrangement. 1. Perform a bacterial smear, as discussed in Figure 3-52 on page 150 of your lab manual. 2. Saturate the smear with basic dye for approximately 1 minute. You may use crystal violet, safranin, or methylene blue. 3. Rinse the slide gently with water. 4. Carefully blot dry with bibulous paper. 5. Observe the slide under the microscope, using proper microscope technique. Negative Stain Negative staining is an excellent way to determine an organism’s cellular morphology. Since the cells themselves are not stained, their morphology is not distorted in any way. The nigrosin provides a dark background against which the shapes of the unstained cells are clearly visible. This method provides a high degree of contrast not available in most other staining procedures. 1. Place a single drop of nigrosin on a clean microscope slide, adjacent to the frosted edge. 2. Using a flamed loop and sterile technique, remove some organism from your tube or plate and mix it into the drop of nigrosin. Be sure there are no large clumps of organism, but try to avoid spreading the drop. 3. Place the end of another clean microscope slide at an angle to the end of the slide containing the organism and spread the drop out into a film. This is done by contacting the drop of nigrosin with the clean microscope slide and using the capillary action of the dye/microscope slide to spread the nigrosin across the smear: 4. Allow the film to air dry. 5. Observe the slide under the microscope, using proper microscope technique