Endospore Staining Lab Report
Endospore and Capsule Cell Staining
Allison Lui
Partner: Mary Chagin
BIOL-235 W07
Dr. Runco
2/10/15
Introduction
The purpose of this lab is to learn what endospore and capsules are, and how to identify them under a microscope using capsule and endospore staining methods.
Capsules are found only in select bacteria, and serve a protective purpose. Made out of sugars and proteins, they are antiphagocytic, which prevents other cells to engulf the bacteria through phagocytosis. It helps the bacterial cell to adhere to host cells, and can help in the formation of biofilm. For the capsule staining, the bacteria Klebsiella Pneumoniae was utilized. It is a facultative anaerobe, meaning it can survive with or without oxygen present. …show more content…
It has two basic cycles: vegetative and sporulation. In the vegetative cycle, a vegetative cell called a sporangium exists. An endospore forms within the cell. When it is fully formed, the endospore lyses out of the sporangium. In the sporulation cycle, the endospore exists. It can withstand extreme temperatures, chemicals, and radiation for thousands of years. Once conditions are favorable again, the endospore germinates and the cycle repeats. In the endospore staining, the bacteria Staphylococcus aureus was used. Due to its hardy nature, heat is used to impart the malachite green stain into both the endospore and vegetative cells. In this lab, the Schaeffer-Fulton method is used, which uses a steam bath to heat the stain. Water is then used to decolorize the vegetative cell, but not the endopore. Safranin is used as a counterstain to give the vegetative cells a pink color, so both are visible under the …show more content…
A drop of nigrosin was added to the near end of the slide. A small drop of K. pneumoniae was added next to, but not touching, the nigrosin. The inoculating loop was used to spread the K. pneumoniae into the nigrosin. Any clumps that were in the mixture were broken up using the loop. A second microscope slide was obtained, and held at an angle against the first horizontal slide. The second slide was pushed backwards towards the mixture of the nigrosin and K. pneumoniae until it made contact. The liquid was then dragged towards the opposite end of the slide, spreading the mixture along the bottom slide. The slide was allowed to air dry. Once dried, it was heat fixed by quickly passing it over the bunsen burner flame three times. The slide was then flooded with crystal violet, and let stain for one minute. It was then washed with water and blotted dry with bibulous paper. Finally, it was observed under the microscope. The stained specimen was located under the lowest objective by using the coarse adjustment knob. While keeping the specimen centered and in focus using the fine adjustment knob, the objectives were increased in power until the oil immersion objective was reached. A drop of oil was added to the slide before viewing under the oil immersion
Allison Lui
Partner: Mary Chagin
BIOL-235 W07
Dr. Runco
2/10/15
Introduction
The purpose of this lab is to learn what endospore and capsules are, and how to identify them under a microscope using capsule and endospore staining methods.
Capsules are found only in select bacteria, and serve a protective purpose. Made out of sugars and proteins, they are antiphagocytic, which prevents other cells to engulf the bacteria through phagocytosis. It helps the bacterial cell to adhere to host cells, and can help in the formation of biofilm. For the capsule staining, the bacteria Klebsiella Pneumoniae was utilized. It is a facultative anaerobe, meaning it can survive with or without oxygen present. …show more content…
It has two basic cycles: vegetative and sporulation. In the vegetative cycle, a vegetative cell called a sporangium exists. An endospore forms within the cell. When it is fully formed, the endospore lyses out of the sporangium. In the sporulation cycle, the endospore exists. It can withstand extreme temperatures, chemicals, and radiation for thousands of years. Once conditions are favorable again, the endospore germinates and the cycle repeats. In the endospore staining, the bacteria Staphylococcus aureus was used. Due to its hardy nature, heat is used to impart the malachite green stain into both the endospore and vegetative cells. In this lab, the Schaeffer-Fulton method is used, which uses a steam bath to heat the stain. Water is then used to decolorize the vegetative cell, but not the endopore. Safranin is used as a counterstain to give the vegetative cells a pink color, so both are visible under the …show more content…
A drop of nigrosin was added to the near end of the slide. A small drop of K. pneumoniae was added next to, but not touching, the nigrosin. The inoculating loop was used to spread the K. pneumoniae into the nigrosin. Any clumps that were in the mixture were broken up using the loop. A second microscope slide was obtained, and held at an angle against the first horizontal slide. The second slide was pushed backwards towards the mixture of the nigrosin and K. pneumoniae until it made contact. The liquid was then dragged towards the opposite end of the slide, spreading the mixture along the bottom slide. The slide was allowed to air dry. Once dried, it was heat fixed by quickly passing it over the bunsen burner flame three times. The slide was then flooded with crystal violet, and let stain for one minute. It was then washed with water and blotted dry with bibulous paper. Finally, it was observed under the microscope. The stained specimen was located under the lowest objective by using the coarse adjustment knob. While keeping the specimen centered and in focus using the fine adjustment knob, the objectives were increased in power until the oil immersion objective was reached. A drop of oil was added to the slide before viewing under the oil immersion