Volutin Granule Staining Technique and its Details
- Micro-organism have a special characteristic these organism store reserve food material in the form of granules.These granules are utilized by these organism when they are in starvation mode.
- These reserve food granules are also called Volutin granules, Metachromatic granules or Babes Ernst granules.
- These granules are mainly of four types.
- Volutin granules.
- Sulphur granules.
- Nitrogenous reserve food material.
- Non-nitrogenous reserve food material.
- These granules are called as Volutin granules because these granules were first observed in Spirillum volutans.
- It is also called as metachromatic granule because if these granules are stain with blue stain they appear red in colour so it has a property of changing colour.
- These granules are made up of proteins, RNA and poly-phosphate molecules .
- Volutin granules are mainly present in bacteria, algae,fungi and protozoa.
- These granules are stain by using Albert’s staining method.
To stain volutin granules by Albert’s staining method.
- Cell suspension.
- Albert’s stain.
- Albert’s iodine.
- Prepare a smear on clean grease free slide.
- Air dry and heat fix the smear.
- Treat the smear with Albert’s stain and allow it to react for about 3 mins .
- Drain of the excess stain do not water wash the slide.
- Flood the smear with Albert’s iodine for 2 minutes.
- Wash the slide with water,air dry and observe under oil immersion lens.
Flow chart of volutin granule procedure
- Albert stain is basically made up of two stains that is Toluidine blue’ O’ and Malachite green.
- The pH of Albert stain is adjusted to 2.8 by using acetic acid.
- As we know cytoplasm of cell has neutral pH so the pH of Albert stain is acidic for cytoplasm.
- Where as pH of Albert stain is basic for Volutin granules as pH of Volutin Granule is highly acidic.
- Therefore when we apply Albert’s stain to the smear the stain Toluidine blue’ O’ stains the most acidic part of cell that is Volutin Granules and Malachite green stains the cytoplasm.
- As we know due to Metachromatic property when granules are stain with blue stain they appear red in colour.
- So here when we apply Albert’s iodine due to effect of iodine the metachromatic property is not observed and granules appear blue in colour.
The volutine granules appear bluish black in colour as well as cytoplasm appear light green in colour.