PARA LAB - LAB SAFETY Flashcards
What is the safest key in the laboratory?
Practice preventive measures
What is Practice Standard Precautions
We have to be careful with all the biological specimens in the laboratory
Examples of Standard Precautions
Handwashing, Usage of PPE
What are the potential risk in the laboratory
- Ingestion of Eggs/Ova
- Skin Penetration of Infective Larva
- Infection of non parasitic agent
What are the Basic Laboratory Rules
- Keep the work areas uncluttered
- Wash your hands with soap and water BEFORE ENTERING AND AFTER LEAVING THE LABORATORY
- Always wear your laboratory coat
- Always wear gloves
- Use proper shoes
- Handle toxic substances under a safety hood
- Labell all preparations and samples to be analyzed
- Dispose of all waste appropriately and safely
- Clean and disinfect the work area
- Do not take out the laboratory notepad and other things inside because they are potentially contaminated
- Do not store food and/or drinks
- Do not eat and/or drink
LABORATORY SAFETY: FIXED STOOL SPECIMEN
Fixed - means it killed all the infectious agent
but some parasites even formalinized may still be infectious
What to do when there is still a presence of Ascaris Egg to Fixed Stool Specimen
Heat the formalin to kill the ascaris egg
Plasmodium Species
causative agent of malaria
Wuchureria
Causative agent of Filariasis
Babesia
Causative agent of Babesiosis
When shoulld blood be collected
Before treatment is initiated
treatment can give u false negative result
T/F when malaria and babesiosis are suspected, blood smears should be examined without delay
True
T/F Multiple blood smears might be needed
True - parasitimua (blood in parasite) can fluctuate
multiple blood smears from different time periods
The microfilariae is found at night time, and
this is seen in Wuchereria. What periodicity is being described
Nocturnal Periodicity
10 pm - 2 am
This is a microfilariae is found at day time, and an example is the Loa Loa. What periodicity is being described?
Diurnal Periodicty
Where is fecal specimen best collected
Clean, wide-mouthed containers
Why should wide-mouthed containers
To easily collect the stool specimen
What is the proper collection of fecal specimen
- do not get the specimen coming from the bowl it might be contaminated - there might be freeliving specimen that might be mistaken as a parasite
- DEFACATE ON A CARDBOARD THEN USE THE SCOOP
- Direct collection is also acceptable but not recommended
What are the necessary information to be submitted in a fecal specimen
- Patient’s name
- Age
- Sex
- Date/Time of collection
- Requesting Physician
- Requested Procedure
- Presumptive diagnosis
- Prior infection
- Travel history
In a fecal specimen where should the label be placed
On the body, not the cap
T/F Intake of antacids, anti-diarrheals, barium, bismuth, laxatives may cause a formation of CRYSTALLINE RESIDUE
True
If a patient has taken antacids, anti-diarrheals, barium, bismuth, laxatives how many days should the patient wait before submitting the specimen
one week after their last drug intake
What residue might be form in the intake of antacids, anti-diarrheals, barium, bismuth, laxatives
crystalline resiudue
Intake of Antibiotics
decreases the number of protozoans
it can be positive / negative depending on the time
What is the best time to collect specimen
Before the patient intakes drugs and antibiotics
Amount of stool to be collected
Dictated by the techniques that will be used
Amount of stool to be collected for routine examination
thumb of an average person
Amount of stool to be collected for watery stool
5-6 tablespoon worth
What to use collecting water stool specimen
Clean ice cream bowl
Processing water stool specimen
Within 30 minutes, must be processed immediately
Why should water stool specimen to be processed within 30 minutes
they must be processed immediately and this is because it might contain PROTOZOAN TROPHOZOITES
Why must contamination with toilet water, urine, or soil must be prevented?
- Can destroy protozoan trophozoites
- May contain free-living organisms that would complicate diagnosis of infections
Why must watery specimen be processed within 30 minutes
may contain protozoan trophozoites that may die 30 minutes to 1 hour after passage
What if there is a delay in specimen examination
Preservative must be added
T/F Trophozoites are killed by refrigeration
True
T/F Protozoans trophoized are usually isolated in water specimen
True
What refrigerator temperature is acceptable
3 - 5 C*
T/F Helminth eggs and protozoan cyst are usally damaged in regfrigerator
False - they are usually not damaged
T/F Freezing stool sample may cause drying and destruction of protozoan parasites
True
T/F The longer we put the specimen in the refrigerator the longer it will dry
True
When putting the specimen in the refrigerator what must be added?
Stool Preservatives
A stool preservative that is an all-purpose fixative and most commonly used
Formalin
T/F Protozoans are inadequately preserved in Formalin
True
T/F 5% concentration is recommendd for helminth eggs and larvae
False - 5% concentration is for protozoan cyst
T/F 10% Concentration is recommended for protozoan cyst
False - 10% concentration is recommended for helminth eggs and larvae
What buffer is used with formalin to preserve the morphological characteristics of organisms
Sodium Phosphate
T/F - Preserved stool can be concentrated using formalin-ether/ethyl acetate concentration technique
True
What is the advantage of FECT
easy to prepare; long shelf life; easily preserves the cysts, eggs, and larvae
What is the disadvantage of FECT
never used for permanent staining; protozoan trophozoites are not fixed or preserved completely (reason why they get destroyed)
What is the best preservative used to preserve fresh stool in the peparation for staining the stool smears
Schaudinn’s Solution - contains mercuric chloride
Advantage of Mercuric Chloride
Used for permanent staining; excellent for preserving the morphology of protozoan cysts and trophozoite
Disadvantage of Mercuric Chloride
Highly toxic to humans;
problems of mercury disposal may arise
What acts as an adhesive and a partner of Schaudinn’s Solution
Polyvinyl Alcohol (PVA)
A plastic resin to adhere stool sample onto a slide
Polyvinyl Alcohol (PVA)
Advantage of PVA
elated to the preservation of protozoan cysts and trophozoites for permanent staining
Disadvantage of PVA
associated with toxicity because of the use of mercuric chloride
What is a substitute for Schaudinn’s solution
Merthiolate-Iodine-Formalin (MIF)
Staining components of MIF
Merthiolate and Iodine
Other term for Merthiolate
Thimerosal
In MIF what acts as a preservative
Formalin
T/F MIF yields lower or unsatisfactory result
True
aside from MIF this is also a substitude for Schaudinn’s Solution
Sodium Acetate-Acetic Acid Formaline (SAF)
Advantage of
Sodium Acetate-Acetic Acid Formalin (SAF)
Not containing mercuric chloride
A liquid fixative with a long shelf-life
Sodium Acetate-Acetic Acid Formalin (SAF)
Disadvantage of SAF
not as sharp after staining compared with those fixed with PVA or Schaudinn’s solution
T/F Some containers already contain preservatives that are readily available in the market
True
PROPER DISPOSAL OF FRESH STOOL SAMPLE
Blood specimens are always soaked first in a 1:10 hypochlorite solution
T/F Decontaminate/Disinfect the blood before discarding
True
T/F yellow waste container is used for anatomical waste (e.g. hand, organs, tissues).
False - red waste container
T/F Red waste container is used for swabs, dressings, aprons, pads, and nappies.
False - Yellow waste container
