Explain the decolourizing agent - stain technique, Biology

Assignment Help:

Explain the Decolourizing Agent - Stain Technique?

95% ethanol is used as a decolourizing agent. It has two functions -

(1) It acts as protein - dehydrating agent, and

(2) It is a lipid solvent. The action of decolourizing agent depends on two factors -

(i) Concentration of lipids in cell wall.

(ii) Thickness of peptidoglycan layer.

In gram negatives, lipid content is high as compared to gram positives, so ethanol action increases the porosity of cell wall by dissolving the lipid layer in outer membrane. Peptidoglycan layer being thinner and less highly cross linked as compared to gram positives, is not able to retain the CV-I complex and cell become colourless. On the other hand, in gram positives, the pores become smaller due to dehydrating effect of the alcohol, so CV-I complex is retained by the thick highly cross linked peptidoglycan layer, and the cells remain purple. This step generates the differential aspect of the gram stain and is very critical.


Related Discussions:- Explain the decolourizing agent - stain technique

Explain fusion inhibitor, Fusion inhibitor  After HIV binds to the host...

Fusion inhibitor  After HIV binds to the host cell surface, a conformational change occurs in the transmembrane glycoprotein sub- unit (gp41) of the viral envelope, facilitatin

Deficiency diseases-sporadic exertional rhabdomyolysis, Sporadic exertiona...

Sporadic exertional  rhabdomyolysis (azoturia, tying up in horses) Azoturia is a metabolic condition of horses that is characterized by reluctance to move and poor performance.

Horse diseases-equine infectious anaemia, Equine infectious anaemia Eq...

Equine infectious anaemia Equine infectious anemia (EIA), an acute or chronic viral disease of the equines, shows intermittent fever, loss of weight, depression, progressive w

Classification of plants and animals, Q. Classification of plants and anima...

Q. Classification of plants and animals? The first and foremost step in the classification of plants and animals is the. grouping together of individual organisms on the basis

Floral apex, Floral Apex Each plant must pass through a minimal 'ripe...

Floral Apex Each plant must pass through a minimal 'ripeness to flower' stage. That is, even to perceive and respond to a specific photoperiodic regime, a plant must be ready

Tanco beans plant, what are the origin, morphology, active constituents, us...

what are the origin, morphology, active constituents, uses and market preparation of tanco beans ?

Explain systolic murmurs in heart diease details, Explain Systolic Murmurs ...

Explain Systolic Murmurs in heart diease details? Definition: Murmurs is a series of auditory vibrations that are more prolonged than a sound. Causes: High-energy turbulence ca

Scope of user charges, Normal 0 false false false EN-IN...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What are diseases of the connective tissue, Q. What are diseases of the con...

Q. What are diseases of the connective tissue? What are some of them? Diseases of the connective tissue are acquired or hereditary diseases numerous of autoimmune cause charact

What is the estimated percentage of water in the human body, Q. What is the...

Q. What is the estimated percentage (in mass) of water in the human body? Is this percentage expected to be larger in the adult or in the old individual? Approximately 65% of t

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd