Whether a bacterium produces spores, as well as the shape and position of the spores, are important identifying characteristics of the bacterium. The spore coat has a more complex, compact structure and lower permeability than the cell wall of vegetative cells, making it more difficult to stain and decolorize. Spores exhibit strong resistance to heat and chemical agents. When basic dyes are applied with heating or extended staining time, both the bacterial cells and spores can be stained. Subsequent rinsing with distilled water removes the stain from the vegetative cells, while the stain in the spores remains retained, allowing for clear differentiation between the morphological features of spores and vegetative cells under a microscope.
Aladdin Spore Crystal Staining Solution is mainly composed of carbolic acid, ethanol, and fuchsin. Spores and crystals will be stained red, whereas the bacterial cells will appear blue. This reagent can be used to determine whether certain bacillus species produce alkali-soluble protein crystals (parasporal crystals). It should be noted that spore observation should be performed during the maturation period, but not excessively late; otherwise, only the spores can be visualized, as the vegetative cells would have already disintegrated. This reagent is intended for research use only and is not suitable for clinical diagnosis or any other purposes.
Materials to Be Prepared by User:
Alcohol lamp, glass slides, inoculation loops, microscope, distilled water
Operating Procedures (For Reference Only):
1. Place 1 drop of distilled water on a clean, grease-free glass slide. Use an inoculation loop to pick a small amount of Bacillus megaterium from the slant culture and mix it thoroughly with the distilled water.
2. Prepare a smear and allow it to air-dry naturally.
3. Add drops of spore-crystal staining solution to cover the smear, ensuring uniform distribution of the bacterial sample, and stain for 1–2 minutes.
4.Rinse the slide gently with water.
5. Microscopic Examination: After drying the slide, observe it under the microscope to check the shape and size of the spores, their position within the bacterial cells, and whether they cause the cells to swell.
Staining Results:
Parasporal crystals
| Red
|
Bacterials
| Blue
|
Notes: Points to Observe During Microscopic Examination:
Morphology
| Round or oval
|
Position
| Central, terminal, or subterminal
|
Size
| Whether the bacterial cells are swollen
|
Precautions:
1. Glass slides must be clean and free of oil stains.
2. Spores are formed during the growth and development phase of bacteria. Observation of spores should be carried out when they reach maturity, but not too late—otherwise, only the spores can be seen, as the vegetative cells will have disintegrated.
3. Handle with care during the staining process to prevent the bacterial sample from detaching from the slide.
4. Avoid high-temperature flame fixation during the sample immobilization step.
5. For your safety and health, wear a lab coat and disposable gloves during the operation.
6. Use the reagent as soon as possible after opening to avoid compromising the results of subsequent experiments.
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