Lactophenol Cotton Blue (LPCB) Staining 50 FAQs and 30 MCQs
Lactophenol Cotton Blue (LPCB) Staining 50 FAQs
What is Lactophenol Blue Stain used for?
It is used as a mounting medium and staining agent for microscopic examination of fungi.
What are the main components of Lactophenol Blue Stain?
Phenol, lactic acid, glycerol, and cotton blue.
Can Lactophenol Blue Stain be used for stool samples?
Yes, it has been evaluated for use in wet mount preparations of stool samples for parasite detection.
What is the shelf life of Lactophenol Blue Stain?
It has a shelf life of 52 weeks when stored at room temperature and protected from light.
Is Lactophenol Blue Stain safe to handle?
Yes, once immersed in the solution, the organism is rendered safe for handling outside of a biological safety hood.
What types of fungal preparations can Lactophenol Blue Stain be used for?
It can be used for teased mounts, mashed mounts, and slide culture preparations.
What is the Tease Mount Procedure?
It involves placing a drop of Lactophenol Blue on a slide, teasing the fungus apart, and covering it with a coverslip.
What is the Scotch Tape Procedure?
It involves pressing transparent tape against a fungal colony, placing it on a slide with Lactophenol Blue, and examining it under a microscope.
Can Lactophenol Blue Stain be used for pigmented moulds?
Yes, a version without cotton blue is available for pigmented strains.
What is the purpose of sealing the coverslip with nail polish?
To preserve the mount as a reference slide.
What are the advantages of using Lactophenol Blue Stain for fungi?
It provides clear staining of fungal structures and is easy to use.
What is the role of phenol in Lactophenol Blue Stain?
Phenol acts as a fixative and kills viable fungi.
What is the role of glycerol in Lactophenol Blue Stain?
Glycerol provides a semipermanent preparation.
What is the role of cotton blue in Lactophenol Blue Stain?
Cotton blue stains fungal elements and internal structures of parasites.
What is the recommended storage condition for Lactophenol Blue Stain?
Store at room temperature and protect from light.
What is the purpose of using Lactophenol Blue Stain in stool examination?
It helps in the detection and identification of parasites in stool samples.
How does Lactophenol Blue Stain compare to saline wet mounts?
It provides better staining of internal structures, making parasites easier to identify.
What parasites can be detected using Lactophenol Blue Stain?
Entamoeba histolytica, Giardia lamblia, hookworm, Ascaris lumbricoides, Trichuris trichiura, Hymenolepis nana, and Taenia species.
What are the advantages of LPCB wet mounts over iodine wet mounts?
LPCB provides deeper staining of cysts and trophozoites, making them easier to detect.
What is the disadvantage of using Lactophenol Blue Stain for stool samples?
Bile-stained helminthic ova lose their natural color and are stained blue.
How does Lactophenol Blue Stain affect polymorphonuclear leukocytes?
It lyses most of them, reducing confusion with parasites.
What is the role of lactic acid in Lactophenol Blue Stain for stool samples?
It kills viable trophozoites, cysts, and ova.
Can Lactophenol Blue Stain be used alongside saline wet mounts?
Yes, it is recommended to use both for comprehensive stool examination.
What is the procedure for preparing an LPCB wet mount for stool samples?
Mix a drop of LPCB with a small volume of stool on a slide and place a coverslip.
How does LPCB stain affect vegetable cells and artifacts in stool samples?
They are stained blue, making them easier to distinguish from parasites.
What is the role of phenol in LPCB for stool samples?
It acts as a fixative and kills viable parasites.
What is the role of glycerol in LPCB for stool samples?
It provides a semipermanent preparation.
What is the role of cotton blue in LPCB for stool samples?
It stains internal structures of parasites, facilitating their identification.
How does LPCB stain compare to Quensel stain for stool samples?
LPCB is simpler, less expensive, and provides better staining of internal structures.
What is the role of distilled water in LPCB stain?
What is the role of distilled water in LPCB stain?
How is Lactophenol Blue Stain prepared?
It is prepared by dissolving cotton blue in distilled water, then adding phenol, lactic acid, and glycerol.
Why is the stain prepared over two days?
To allow insoluble dye to settle out on the first day.
What equipment is needed to prepare Lactophenol Blue Stain?
A magnetic stirrer, glass beaker, and gloves are required.
What is the purpose of filtering the cotton blue solution?
To remove insoluble dye particles.
How often should quality control be performed on Lactophenol Blue Stain?
Regularly, using known reference organisms.
What is the purpose of quality control for Lactophenol Blue Stain?
To ensure the performance of the mounting solution.
What are the ingredients of Lactophenol Blue Stain?
Cotton blue, phenol crystals, glycerol, lactic acid, and distilled water.
What is the role of lactic acid in the preparation of Lactophenol Blue Stain?
What is the role of lactic acid in the preparation of Lactophenol Blue Stain?
What is the role of glycerol in the preparation of Lactophenol Blue Stain?
It provides viscosity and helps in creating a semipermanent mount.
What is the role of phenol in the preparation of Lactophenol Blue Stain?
It acts as a preservative and fixative.
What magnification is used to examine LPCB wet mounts?
Low-power (10x) and high-power (40x) objectives are used.
What structures are visible in LPCB-stained fungal mounts?
Spores, conidia, and other morphological features.
What structures are visible in LPCB-stained stool mounts?
Trophozoites, cysts, and ova of parasites.
How does LPCB stain improve the visibility of parasites?
It stains internal structures deep blue, making them easier to identify.
What is the advantage of LPCB stain for low-power microscopic screening?
It makes parasites more visible, reducing the chance of missing them.
What is the disadvantage of LPCB stain for bile-stained helminthic ova?
They lose their natural brown color and are stained blue.
How does LPCB stain affect the motility of trophozoites?
It kills them, so motility is not observed.
What is the role of the coverslip in LPCB wet mounts?
It flattens the specimen and prevents air bubbles.
What is the purpose of using gauze in the Scotch Tape Procedure?
To smooth the tape on the slide.
What is the advantage of LPCB stain for training students in microscopy?
It reduces eyestrain and makes parasites easier to detect.
Lactophenol Cotton Blue (LPCB) Staining 30 MCQs
- What is the primary use of Lactophenol Blue Stain?
a) Staining bacteria
b) Mounting and staining fungi ✔
c) Detecting viruses
d) Staining parasites in blood - Which of the following is NOT a component of Lactophenol Blue Stain?
a) Phenol
b) Lactic acid
c) Glycerol
d) Ethanol ✔ - What is the role of cotton blue in Lactophenol Blue Stain?
a) Acts as a fixative
b) Stains fungal elements ✔
c) Kills bacteria
d) Preserves the slide - Which procedure is used for preparing a temporary fungal mount?
a) Tease Mount Procedure ✔
b) Gram Staining
c) Acid-Fast Staining
d) Ziehl-Neelsen Staining - What is the purpose of sealing the coverslip with nail polish?
a) To prevent evaporation
b) To preserve the mount as a reference slide ✔
c) To enhance staining
d) To kill the fungi - Which of the following is a limitation of the Scotch Tape Procedure?
a) It is a permanent mount
b) It is a temporary mount and will dissolve eventually ✔
c) It cannot be used for fungi
d) It requires a special microscope - What is the shelf life of Lactophenol Blue Stain when stored properly?
a) 12 weeks
b) 26 weeks
c) 52 weeks✔
d) 104 weeks - Which of the following is true about Lactophenol Blue Stain?
a) It can only be used for pigmented moulds
b) It is used for both fungal and stool examinations ✔
c) It is toxic and cannot be handled safely
d) It is only used for bacterial staining - What is the role of phenol in Lactophenol Blue Stain?
a) Staining agent
b) Fixative and killing agent ✔
c) Solvent
d) Preservative - Which of the following is NOT a fungal preparation method using Lactophenol Blue Stain?
a) Tease Mount
b) Scotch Tape Procedure
c) Gram Staining ✔
d) Slide Culture
- What is the primary purpose of using Lactophenol Blue Stain in stool examination?
a) To detect bacteria
b) To identify parasites ✔
c) To stain viruses
d) To detect fungal infections - Which of the following parasites can be detected using Lactophenol Blue Stain?
a) Entamoeba histolytica
b) Giardia lamblia
c) Hookworm
d) All of the above ✔ - What is the advantage of LPCB wet mounts over saline wet mounts?
a) Better staining of internal structures ✔
b) Preservation of motility
c) Lower cost
d) Faster preparation time - What is the disadvantage of using Lactophenol Blue Stain for stool samples?
a) It cannot detect parasites
b) Bile-stained helminthic ova lose their natural color ✔
c) It is toxic to handle
d) It requires special equipment - Which of the following is true about LPCB wet mounts?
a) They are permanent mounts
b) They are temporary mounts ✔
c) They cannot be used for stool samples
d) They are only used for fungal staining - What is the role of lactic acid in LPCB for stool samples?
a) Staining agent
b) Fixative and killing agent ✔
c) Solvent
d) Preservative - Which of the following is NOT a component of LPCB stain?
a) Phenol
b) Lactic acid
c) Glycerol
d) Ethanol ✔ - What is the primary advantage of LPCB stain for low-power microscopic screening?
a) It makes parasites more visible ✔
b) It preserves motility
c) It is cheaper
d) It is faster to prepare - Which of the following is a disadvantage of saline wet mounts?
a) Poor visibility of internal structures ✔
b) High cost
c) Toxicity
d) Long preparation time - What is the role of glycerol in LPCB stain?
a) Staining agent
b) Fixative
c) Provides a semipermanent preparation ✔
d) Kills parasites
- How long does it take to prepare Lactophenol Blue Stain?
a) 1 hour
b) 1 day
c) 2 days ✔
d) 1 week - What is the purpose of filtering the cotton blue solution?
a) To remove insoluble dye particles ✔
b) To enhance staining
c) To kill bacteria
d) To preserve the stain - Which of the following is required to prepare Lactophenol Blue Stain?
a) Magnetic stirrer ✔
b) Centrifuge
c) Autoclave
d) Incubator - What is the purpose of quality control for Lactophenol Blue Stain?
a) To ensure the performance of the stain ✔
b) To reduce cost
c) To speed up preparation
d) To enhance staining - Which of the following is used for quality control of Lactophenol Blue Stain?
a) Known reference organisms ✔
b) Saline solution
c) Iodine stain
d) Distilled water - What is the role of distilled water in LPCB stain preparation?
a) To dissolve cotton blue✔
b) To act as a fixative
c) To kill parasites
d) To enhance staining - Which of the following is true about the preparation of Lactophenol Blue Stain?
a) It is prepared in one step
b) It requires heating
c) It is prepared over two days ✔
d) It cannot be stored - What is the role of phenol crystals in LPCB stain?
a) Staining agent
b) Fixative and preservative ✔
c) Solvent
d) Enhances motility - Which of the following is NOT a step in the preparation of Lactophenol Blue Stain?
a) Dissolving cotton blue in distilled water
b) Adding phenol crystals to lactic acid
c) Filtering the solution
d) Autoclaving the solution ✔ - What is the recommended storage condition for Lactophenol Blue Stain?
a) Refrigerated
b) Room temperature, protected from light ✔
c) Frozen
d) Exposed to sunlight
Possible References Used
