What is the counterstain in spore staining?
A counterstain to differentiate the vegetative cells is commonly 0.5% safranin. In the end, a proper smear would show the endospore as a green dot within either a red or pink-colored cell. Terbium can also used to detect endospores, as it acts as an assay of dipicolinic acid based on photoluminescence.
What is the counterstain in the Schaeffer Fulton method of spore staining?
The primary stain is malachite green, and the counterstain is safranin, which dyes any other bacterial bodies red. The Schaeffer- Fulton endospore stain uses heat to drive the primary stain(malachite green) into the endospore.
What is the function of malachite green in spore staining?
The presence of endospores in a bacterial culture can be detected by staining with malachite green. Because the endospore coat is so tough, steam is used to enable dye penetration. After washing, only the endospores will retain the primary stain Malachite green.
What type of stain is malachite green?
Because of their tough protein coats made of keratin, spores are highly resistant to normal staining procedures. The primary stain in the endospore stain procedure, malachite green, is driven into the cells with heat.
What is the principle of spore stain?
Principle: Endospore staining is a differential staining technique where the spore is stained in a manner so that it can be distinguished from the vegetative part of the cell. Spores are structures remarkably resistant to heat, radiation, chemicals and other agents that are typically lethal to the organism.
What is the aim of spore staining?
The main purpose of endospore staining is to differentiate bacterial spores from other vegetative cells and to differentiate spore formers from non-spore formers.
What happens if you use safranin as the primary stain and malachite green as the Counterstain?
Malachite green is water soluble and has a low affinity for cellular material, so vegetative cells may be decolourized with water. Safranin is then applied to counterstain any cells which have been decolorized. At the end of the staining process, vegetative cells will be pink, and endospores will be dark green.
What is Malachite Green used for in fish?
It is most effective against external parasites, particularly when combined with formaldehyde. Malachite Green is also quite effective in controlling fungus on fish eggs. Disorders treated by Malachite Green include the following: Egg Fungus – Serves as a safe disinfectant for fish eggs.
How do you make Malachite Green dye?
Malachite green is prepared by the condensation of benzaldehyde and dimethylaniline to give leuco malachite green (LMG): C6H5CHO + 2 C6H5N(CH3)2 → C6H5CH(C6H4N(CH3)2)2 + H2O.
What color is a spore forming bacteria?
Mature spores stain green, whether free or still in the vegetative sporangium; vegetative cells and sporangia stain red. Endospores do not form normally during active growth and cell division.
Why do mother cells not pick up malachite green stain?
Since malachite green is water-soluble and does not adhere well to the cell, and since the vegetative cells have been disrupted by heat, the malachite green rinses easily from the vegetative cells, allowing them to readily take up the counterstain.
How is malachite green used in endospore staining?
Malachite green is water soluble and has a low affinity for cellular material, so vegetative cells may be decolourized with water. Safranin is then applied to counterstain any cells which have been decolorized.
What kind of stain is used to stain endospores?
A primary stain (malachite green) is used to stain the endospores. Because endospores resist staining, the malachite green will be forced into (i.e, malachite green permeate the spore wall) the endospores by heating. In this technique heating acts as a mordant.
What should endospores look like when counter stained with safranin?
When counter-stained with safranin, the vegetative cells take the color of safranin and appear red or pink, in contrast to the endospores that appear green. When visualized under microscopy the cells should have three characteristics: the vegetative cells should appear pink/red (i.e. the color of counterstain),
When did Shaeffer and Fulton invent the endospore stain?
In 1922, Dorner published a method for staining endospores. Shaeffer and Fulton modified Dorner’s method in 1933 to make the process faster The endospore stain is a differential stain which selectively stains bacterial endospores.