acid fast stain
The acid-fast stain is performed on samples to demonstrate the characteristic of acid fastness in certain bacteria. Acid fastness is a characteristic that is shared by just a few organisms, so staining to determine if organisms possess this trait is useful in microbial identification schemes. The Ziehl-Neelsen method has endured as a reliable and effective way to demonstrate the acid-fast bacteria.
Materials:
18-20 nutrient hour agar slant culture of Staphyloccus aureus
4 day old nutrient agar slant culture of Mycabaterium smegmatis
Hot plate and beaker
Inoculating needle and loop
Bibulous paper
Carbolfuchsin
Acid- alcohol
Methylene blue
Staining procedure:
Fill beaker 2/3 full with water. Place beaker on top of hot plate, set to high. Place 2 drops of water on the left side of a clean slide. Transfer some of the growth from the slant M. smegmatis into the water. Break up this growth with the tip of the inoculating needle. Then place 2 drops of water on the right side of the slide, transfer some of the growth from the slant S. aureus into the drop of water. Mix both cultures on the slide with an inoculating loop to make a mixed smear. Air dry and heat fix this smear. Cut a sheet of bibulous paper to fit the dimension of the slide and place this paper on top of smear. When water is boiling, place the paper-covered slide on top of the beaker. Add carbolfuchin to the paper covering the smear. Steam the preparation for 10-12 minutes. Do not let the paper dry out. Add more carbolfuchin to keep the paper wet while steaming. At the end of the streaming, discard the paper in a microbiological waste discard bin. Allow the slide to cool. Tilt the slide. Drip the acid-alcohol onto the smear so that it runs off the smear. The pink color of the primary stain will wash off the smear will become lighter. When this edge is colorless, thoroughly rinse the slide with water to stop further Some bacteria contain a waxy lipid, mycolic acid, in there cell wall. This
Materials:
18-20 nutrient hour agar slant culture of Staphyloccus aureus
4 day old nutrient agar slant culture of Mycabaterium smegmatis
Hot plate and beaker
Inoculating needle and loop
Bibulous paper
Carbolfuchsin
Acid- alcohol
Methylene blue
Staining procedure:
Fill beaker 2/3 full with water. Place beaker on top of hot plate, set to high. Place 2 drops of water on the left side of a clean slide. Transfer some of the growth from the slant M. smegmatis into the water. Break up this growth with the tip of the inoculating needle. Then place 2 drops of water on the right side of the slide, transfer some of the growth from the slant S. aureus into the drop of water. Mix both cultures on the slide with an inoculating loop to make a mixed smear. Air dry and heat fix this smear. Cut a sheet of bibulous paper to fit the dimension of the slide and place this paper on top of smear. When water is boiling, place the paper-covered slide on top of the beaker. Add carbolfuchin to the paper covering the smear. Steam the preparation for 10-12 minutes. Do not let the paper dry out. Add more carbolfuchin to keep the paper wet while steaming. At the end of the streaming, discard the paper in a microbiological waste discard bin. Allow the slide to cool. Tilt the slide. Drip the acid-alcohol onto the smear so that it runs off the smear. The pink color of the primary stain will wash off the smear will become lighter. When this edge is colorless, thoroughly rinse the slide with water to stop further Some bacteria contain a waxy lipid, mycolic acid, in there cell wall. This