21⟩ Tell me what Are The Articles Sterilized In A Hot Air Oven?
Glassware’s, metallic instruments like scissors and forceps, swabs. powder. oils and grease.
Bacteriologist
Home Health Care Bacteriologist
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22⟩ Explain me how Are Stains Classified?
Stains are classified based on the pH of their chromophore (color bearing ion) into acidic, basic and neutral. Acidic dyes have anionic chromophore
eg.. sodium+ eosinate-. Basic dyes have cationic chromophore eg.. metFiylene blue+ chloride-. Acidic dyes combine more strongly with cytoplasmic components of bacteria, especially the nucleus that is basic in nature. Neutral dyes have both acidic and basic component that nullity each other.
They are Romanowsky’s stain and are used in staining parasitic forms. Stains can be either natural (eg: carmine and hematoxylin) or coal-tar derivatives /aniline stains (eg: methylene blue. crystal violet). Supravital (cells removed from the body) and intravital (cells still a part of the body).
23⟩ Do you know what Is Meant By Cold Sterilization?
Use of high-energy radiation such as gamma rays to sterilize an article.
24⟩ Explain what Are The Uses Of Inspissator?
It disinfects and solidifies egg and serum containing media such as U medium and LoelTiers serum slope.
25⟩ Tell me how Are Hemodialyzers And Endoscopes Disinfected?
Glutaraldehyde or a combination of peracetic acid and hydrogen peroxide can be used.
26⟩ What is alveolar Macrophage?
A highly active and aggressive phagocytic macrophage, located on the epithelial lining of the lung alveoli, which ingests and destroys any inhaled particles and micro-organisms.
27⟩ Do you know which Is The Best Disinfectant Used In Serology?
Sodium hypochlorite or Calcium hypochlorite
28⟩ Do you know how Are Heat Labile Fluids Such As Serum And Antibiotic Solutions Sterilized?
By filtration.
29⟩ Do you know what Is The Temperature And Time Employed To Sterilize The Articles In Hot Air Oven?
160°C for 60 mInutes
30⟩ Tell us what Are The Precautions To Be Taken While Preparing Or Observing Smears For Afb?
☛ A new slide must be used for every specimen. because scratch marks may give false positive.
☛ A uniform smear from thick portion of the sputum must be made.
☛ Staining jars should not be used to staining smear as there is risk to cross contamination
☛ Fresh blotting paper must be used for each smear for drying the slide to prevent transfer from one slide to another.
31⟩ Tell me what Are The Conditions When Gram Positive Bacteria Can Appear Gram Negative?
☛ When over-decolourized by either prolonged exposure to decolourizer or using acetone alone.
☛ When cell wall gets damaged by exposure to lysozyme or cell wall acting antibiotics such as Penicillin.
☛ Old cultures, where cell wall is weakened or action of autolytic enzymes
☛ Those bacteria that are phagocytosed. where cell wall is acted upon by lysosomal contents
32⟩ What is abiotic Factors?
Non-living factors that can affect life, like soil, nutrients, climate, wind etc.
33⟩ Tell me how Are The Articles Commercially Sterilized?
Gamma rays. Electron beams and Ethylene oxide
34⟩ Explain me which Are The Ways To Demonstrate These Granules?
Albert’s stain. Neissers stain, Ponder’s stain and Pugh’s stain They can be demonstrated as retractile bodies in wet mount or slightly more gram positive structures in Gram stain.
35⟩ Tell us which Are The Positive And Negative Controls For Gram Stain?
☛ Positive control: Staphylococci
☛ Negative control: E.coli. pus cells
36⟩ Tell us what Do Popular Brands Of Antiseptics Such As Dettol Or Savlon Contain?
The active ingredient of Dettol is chloroxylenol whereas Savlon contains a combination of Cetrimide and Chiorhexidine.
37⟩ Tell me what Are The Various Filters?
Porcelain filters. Seitz (asbestos) filters. Sintered glass filters. Membrane filters and HEP filters.
38⟩ What is agar?
A dried hydrophilic, colloidal substance extracted from red algae species, used as a solid culture media for bacteria and other micro-organisms. Also used as a bulk laxative, in making emulsions and as a supporting medium for immunodiffusion and immunoelectrophoresis
39⟩ Tell us how To Interpret The Smear?
At least 100 oIl Immersion fields must be viewed before declaring the smear as negative The sensitivity of smear Is low because It requires the presence of 104 bacillilml to be smear positive. If the number of bacilli is less than this, the chances of detecting them are less In such a case, the sample should be subjected to concentration techniques such as Petroff s method If the smear Es positive for AFB. it should be counted/graded Failure to detect any AFB does not rule tuberculosis Grading of smears has prognostic value.
40⟩ Explain me who Introduced Acid Fast Staining?
Ehrlich in 1882 discovered acid fastness. The original method involved staining with aniline-gentian violet and decolourization with strong nitric acid.
It was later improved by Ziehl and Neelsen.
