Acid-Fast Staining {Lab 6 - May 19, 2015}

     Today the stain we used was an acid-fast stain on our unknown and a sample of TB for comparison. This time Clare and I both prepared each sample.

Materials: 

Our unknown being stained
methylene blue

• slide 
• inoculating loop
• Bunsen burner 
• forceps 
• boiling beaker
• staining rack
• Ziehl-Neelsen carbolfuchsin 
• de-coloring acid-alcohol
• DI water
• methylene blue
• Bibulous paper

Procedure:  

     As usual with staining, the first thing we had to do was to fix a smear of our samples. However, today we tried something new to make the process faster: we fixed both samples on the same slide. After the smears were fixed, the first part of the process was to place the slides on a staining rack over steaming water. Covering them with the bibulous paper, we proceeded to cover the paper with Ziechl-Neelsen carbolfuchsin. For the next 3-5 minutes we continued to keep the paper wet as the water steamed up under the slides. When it was time, we rinsed the Ziechl-Neelsen carbolfunchsin with DI water. Following this stain, the decolorizing acid-alcohol was used to further wash off the stain. Next up was the methylene blue. This one needed to sit for 2 minutes before being washed off. When this was done, the slide was blotted dry with the Bibulous paper and the slides were ready for the microscope.

Tuberculosis Acid-Fast Stain 

Results: 

Negative Acid-Fast Stain of our Unknown

     The TB was used as a control to see what a positive result for an acid-fast stain would be. Both Clare and I observed two colors red and blue mix together on the TB acid-fast stain. Now that we knew what to look for, we examined our unknown. The unknown was stained only a blue color; therefore, we can conclude that our unknown is a non-acid-fast in its lipid content of its cell wall.The acid-fast stain is a laboratory test that determines if a sample of tissue, blood, or other body substance is infected with the bacteria that causes tuberculosis and other illnesses.