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Group: Laboratory Medicine

Subject: Laboratory Technique (Paper-I)

Q-1-a) Write down the Professional Conduct of laboratory technologist. (Jan-2021)


A Code of Professional Conduct for Medical Laboratory Personnel should include those practices and attitudes which characterize a professional and responsible laboratory officer.

It is necessary to ensure a person works in recognized standards which patients and clinicians expect.

It also emphasizes the professional status of medical laboratory practice.

It can keep motivation alive and reminds the personnel that the medical laboratory profession is dedicated.

Professional code of conduct for medical laboratory personnel: 

  • Be dedicated to the use of clinical laboratory science to benefit mankind.
  • Place the well-being and service of patients above your own interests. 
  • Be accountable for the quality and integrity of clinical laboratory services. 
  • Exercise professional judgment, skill, and care while meeting established standards.
  • Do not misuse your professional skills or knowledge for personal gain, and never take anything from your place of work that does not belong to you. 
  • Be at all times courteous, patience and considerate to patients and their relatives. Safeguard the dignity and privacy of patients.
  • Do not disclose to a patient or any unauthorized person the results of your investigation and treat with strict confidentiality any personal information that you may learn about a patient. 
  • Respect and work in harmony with the other members of your hospital staff or health centre team. 
  • Promote health care and the prevention and control of disease.
  • Follow safe working practices and ensure patients and others are not put at risk. Know what to do if an accident or fire occurs and how to apply emergency First Aid. 
  • Do not consume alcohol or take unprescribed drugs that could interfere with your work performance during laboratory working hours or when on emergency stand-by.
  • Use equipment and laboratory-ware correctly and do not waste reagents or other laboratory supplies. 
  • Strive to improve professional skills and knowledge and adopt scientific advances that benefit the patient and improve the delivery of test results. 
  • Fulfill reliably and completely the terms and conditions of your employment.
Q-1-b) Mention the guideline for collection of specimen. (Jan-2021)

Guideline for collection of specimen:

There are four steps involved in collection of good quality specimens for testing:

1. Preparation of the patient

2. Collection of the specimen

3. Processing the specimen, and

4. Storing and/or transporting the specimen.

General instructions for specimen collection:

  • Selection of appropriate sites for specimen collection (e.g., the concentration of glucose is different in arterial and venous blood).
  • To ensure that the most useful specimen is obtained, it should always be collected at the appropriate time. Random collection should be limited to emergency situations. 
  • Use the container/tube indicated in the test requirements for appropriate specimen preservation (e.g, blood for cell counting should be collected in tubes containing EDTA dipotassium salt to avoid plasma coagulation and platelet aggregation). 
  • Collect a quantity of specimen sufficient to perform the test, as indicated in the rest requirements.
  • Specimens should be collected under strict aseptic conditions where necessary.
  • Specimens should be collected in dry, sterile, leak proof containers free from all traces of disinfectant.
  • Carefully tighten specimen container lids to avoid leakage and/or potential contamination of specimens.
  • High risk specimens, e.g. blood, sputum,  fluid from ulcers – must be handled with extra care.
  • Maintain the specimen at the temperature indicated in the test requirements. 
  • All specimens should be labeled in the presence of the patient.

Processing the specimen:

Process and store the specimens  as required. Appropriate storage and handling are necessary to maintain integrity of the specimen and, consequently, the test results.

Q-1-c) Define oxygen therapy. State the procedure of  oxygen therapy. (Jan-2021)

Oxygen therapy:

Oxygen therapy is the administration of oxygen at concentration greater than that in room air to treat or prevent low oxygen in the blood (hypoxemia).


Oxygen therapy:

Oxygen therapy is a medical treatment that provides supplemental oxygen to people who cannot get enough oxygen on their own.

Methods of oxygen administration:

  1. Nasal cannula – A thin tube with two small nozzles that protrude into the patient’s nostrils.
  2. Simple face mask.
  3. Partial rebreathing mask (face mask with a reservoir bag)
  4. Transtracheal catheter (endotracheal tube)
  5. Oxygen tent

Method of oxygen therapy by nasal cannula:

Articles required: A tray containing –

  • Nasal cannula – 2 (clean and sterile)
  • Lubricant in a bowl
  • Bowl of warm water
  • Adhesive tape 
  • Swab sticks
  • Gauze pieces 
  • Oxygen cylinder

General instructions:

  1. Written order for O₂ therapy with specific dose must be given by a physician.
  2. Adjust the flow of O₂ (2-4 l/min for adults). 
  3. The cannula should be changed, at least, 8 hourly to avoid block of cannula .
  4. The cannula may be taped to the forehead for comfort of the patient to keep it in place.
  5. The nose of the patient should be lubricated with jelly if there is any sign of irritation.
  6. Observe the patient receiving oxygen therapy continuously to detect any sign of oxygen toxicity.


  • Handle the cylinder with care. Cylinder stand should be used to prevent falling of the cylinder.
  •  Fire precautions are to be taken when O2 is on flow.
  • O2 cylinders should be stored at a low temperature.
Q-1-d)  What is cross infection? How will you prevent laboratory cross infection? (Jan-2021)

Cross infection:

Cross infection (or laboratory acquired infection) is the transfer of harmful microorganisms, usually bacteria and viruses, from the patients, specimens, equipment, or place to the laboratory staff while working in the laboratory.


Cross infection:

Cross infection, also known as cross contamination, is the transfer of harmful microorganisms, such as bacteria and viruses, from one person to another. This can happen through direct contact, indirect contact, or through the air.

Prevention of cross infection:

1. Practice of personal hygiene and reducing contact with infected materials.

  • Washing of hands:
  • Using soap and warm water. Rub the hands really well for at least 20 seconds. Rupp the palms fingernail, in between the fingers, and the backs of the hands.
  • If hands do not look dirty, alcohol-based sanitizers are used to clean hands. Rub the sanitizer all over the hands, especially under the nails and between the fingers, until the hands are dry.
  • Hands are cleaned before and after doing a procedure, before touching or eating food etc.
  • Wearing gloves when the laboratory workers perform tasks such as taking blood, touching wounds or body fluids. 
  • Covering of mouth and nose using face mask to prevent entry of organisms.

2. Safe working environment: 

  • Careful handling of specimens, cultures and other infected materials.
  • Pouring infectious material safely.
  • Avoiding mouth pipetting and dispensing. 
  • Opening cultures and ampoules safely.
  • Shaking cultures and infected materials safely in tightly capped bottles. 
  • Avoiding infection from centrifuge accidents.
  • Avoiding infection from spillages and breakages.
  • Safe use of syringes and needles.
  • Safe disposal of specimens and contaminated materials.
  • Decontamination of all surfaces and reusable devices after use with appropriate disinfectants.

3. Immunization against highly infectious pathogens and regular medical examination of the laboratory personnel.

Q-1-e) What is the indication of blood transfusion?. Name some disease which transmitted by blood transfusion? (Jan-2021)


 Indication of blood transfusion:

  • Anaemia, leukaemia, idiopathic thrombocytic purpura (ITP).
  • Major surgical operation.
  • Accidents resulting in considerable blood loss.
  • Cancer patients requiring therapy.
  • Women in childbirth and newborn babies in certain cases.
  • Hereditary blood disorders like Haemophilia and Thalassaemia.
  • Severe burn.

Disease  transmitted by blood transfusion:

  • Hepatitis B and C
  • Syphilis
  • Malaria
  • Chagas disease
Q-2-a) What are the responsibilities of a medical technologist? (Jan-2021)

The responsibilities of a medical laboratory technologist are to:

  • keep the laboratory clean and secured.
  • Maintain safety of the laboratory staff.
  • Maintain safety of the patients attending the laboratory.
  • Receive the attending patients cordially and politely.
  • Behave well with the patients and their attendance coming to the laboratory. 
  • Explain the procedure and consequence of the test to the patients and their attendance if needed.
  • Motivate and counsel the patients, if needed. 
  • Take consent of the patient and/or the attendant where necessary.
  • Keep the chemicals, equipment and glassware safely at the places marked for them.
  • Handle the equipment with care.
  • Label the chemicals’ bottles and reagents properly and handle them with care.
  • Clean and sterilize the materials as required.
  • Dispose of the specimens and infected materials in a safer manner.
  • Continue updating of laboratory facilities and also responsible for quality control of the laboratory.
  • Maintain the patients’ register.
  • Prepare indent for essentials.
  • Collect essential logistics and to maintain a register. 
  • Coordinate and cooperate with related other departments.
Q-2-b) Name the different parts of a compound microscope with care. (Jan-2021)


Parts of a compound Microscope : 

  1. Mechanical parts 
  2. Optical parts 

1. Mechanical parts:

  1. Base (পদদেশ ) 
  2. Pillar (স্তম্ভ) 
  3. Arm (বাহু/তল ) 
  4. Body tube (দেহ নল) 
  5. Coarse adjustment screw 
  6. Fine adjustment Screw 
  7. Draw tube (টানা নল)
  8. Stage(মঞ্চ)   
  9. Slide clip
  10. Slide Screw 
  11. Stage screw 
  12. Condenser Screw

2. Optical parts :

  1. Eyepiece
  2. Objective 
  3. Condensar 
  4. Mirror 
  5. Objective lens 
  6. Diaphragm 

Microscope Objective are four (4) types :

  1. Scanner : 4x : Histo & Cytopathological Slide দেখা হয়।
  2. Low (dry) : 10x : Balancing of magnification and working distance.
  3. High (dry) :  40x : Blood cell, Urine Slide, Stool slide দেখা হয়।
  4. Oil immersion :100x : Bacteria দেখা হয়।

Care of microscope :

1. Examine all the parts of a microscope before use.

2. Keep the microscope in a perfectly clean condition.

3. Carry by holding the arm.

4. Clean the lenses with a Soft Cotton Cloth moistened with xylol. Remove xylol with a dry cloth without delay.

5. Clean the oil-immersion objective on each occasion after use, by wiping the oil from the front of the Lens with a cloth.

Q-2-c) Name five superficial veins from which blood is collected.(Jan-2021)

Sites of Blood Collection:

The blood sample is collected either from a vein or a capillary. Very rarely arterial blood samples are used.

1. Capillary blood is also called ‘peripheral blood’ as it comes out of the peripheral vessels (capillaries).

Sites of peripheral blood collection:

  • Fingertips
  • Lobule of the ear,
  • In infants – the heel, thumb pad, or greater toe.

2. Venous blood is usually collected from the superficial veins in adults, such as:

  • Median cubital vein
  • Cephalic vein 
  • Basilic vein
  • Dorsal venous arch (in the dorsum of the hand)
  •  Great saphenous vein (in front of the medial malleolus)

                     ■ In children: femoral vein, scalp vein.

                     ■ In newborn children: umbilical vein and scalp vein. 

3. Arterial blood is usually collected from radial artery or femoral artery.

Q-2-d) Name the instruments and reagents used for TC, DC of WBC. (Jan-2021)


Instruments used for TC of WBC:

  • Microscope
  • WBC pipette
  • Blood lancet/needle
  • Spirit/alcohol
  • Improved Neubauer counting chamber
  • Sterile cotton

Reagents used for TC of WBC:

  • WBC diluting fluid

Instruments used for DC of WBC:

  • Microscope
  • Glass slide
  • Spreader
  • Staining rack
  • Blood lancet/needle
  • Spirit/alcohol
  • Sterile cotton

Reagents used for DC of WBC:

  • Leishman’s staining solution
  • Distilled water
Q-2-e) Define medical record. What are the importance of record keeping? (Jan-2021)

 Medical record: The reports and documents of different laboratory tests and medical activities that are maintained in a register are called medical records.


A medical record is a document that contains a patient’s medical history, including their medical problems, medications, allergies, immunizations, surgeries, and test results. It also includes information about the patient’s care, such as their diagnoses, treatments, and progress.

Importance of medical recording keeping:

  • In the laboratory, medical records help to find out a patient’s test results quickly.
  • Test records are required to prepare work reports and to estimate the workload of the laboratory.
  • Help to identify a patient in case of need.
  • Help to prepare a list of patients according to age sex.
  • Help to prepare a list of the diseases occurring in an area.
  • Help to prepare a future plan in the medical field for better service.
Q-3-a) What are the difference between chemical and reagent? (Jan-2021)


Difference between chemical and reagent:


A substance with a specific chemical composition and properties.A substance or mixture used in a chemical reaction or analysis.

Role in a chemical reaction
Can be a reactant, product, solvent, or catalystCan be a reactant, product, or solvent. Catalysts are not considered reagents

To be used in chemical reactions, industrial processes, or other applications.To be used in chemical reactions or analyses.

Water, sodium chloride, sulfuric acid, benzeneBenedict’s reagent, Tollens’ reagent, Fehling’s reagent, silver nitrate
Q-3-b) Name the tests for covid-19. How to collect specimen for the test. (Jan-2021)



There are different types of COVID-19 tests-diagnostic tests and antibody tests.

1. Diagnostic tests:

Diagnostic tests can show if you are currently infected with SARS-CoV-2, the virus that causes COVID-19. There are two types of COVID-19 diagnostic tests:

  • Molecular tests [Nucleic acid amplification tests (NAATs)], such as polymerase chain reaction (PCR) tests RT-PCR test
  • Antigen tests, often referred to as rapid tests (detect specific proteins on the surface of the virus.)

2. Antibody test (serological test) – This test checks for antibodies to COVID-19.

COLLECTION OF SPECIMEN (nasophryngeal/oropharyngeal swab)FOR COVID-19 TEST:

Procedure To Collect Nasopharyngeal Swab:

  • Firstly, the patient is asked to take off his/her mask and blow the nose into a tissue to clear the nasal passage. Then, slowly tilt the patient’s head back slightly (70 degrees) to access the nasal passage.
  • A minitip swab with a flexible shaft (wire or plastic) is inserted gently and slowly through the nostril parallel to the palate (not upwards) until resistance is encountered or the distance is equivalent to that from the ear to the nostril of the patient, indicating contact with the nasopharynx.
  • The swab is gently rubbed and rolled. 
  • The swab should be left in place for few seconds to absorb secretions and then slowly removed while rotating it.
  • Finally, the swab should be placed in the VTM and the shaft should be broken.

Procedure To Collect Oropharyngeal Swab:

For collecting oropharyngeal swabs, we need to ask the subject to open his or her mouth wide open. The tongue should be depressed using a tongue depressor and the posterior pharynx behind the tonsils should be swabbed, avoiding the tonsils. The OP swab should elicit a gag reflex, but there is much person to person variability in the gag response. Swabs should be kept in place for 10 seconds while twirling the swab three times. The collected swab should be placed into the same VTM and shaft needs to be broken.

Q-3-c) Name some anticoagulants with their uses. (Jan-2021)

 Common anticoagulants with their uses:

                  Anticoagulants                            Uses
1. Double oxalates (Ammonium oxalate and Potassium oxalate)Tests done by using double oxalates are -HaemoglobinWBC count, RBC countEstimation of ESR by Wintrobe’s methodPCV determinationBiochemical tests, except blood urea estimation.
2. EDTA (Ethylene diamine tetraacetic acid)Tests done by using EDTA are -Haemoglobin WBC count (total and differential), RBC countPCV determinationESR by Wintrobe’s methodPlatelet countDifferential count of WBC
3. Tri-sodium citrateESR by Westergren’s methodCoagulation studies
4. HeparinDetermination of blood gasses Osmotic fragility test
5. Oxalated fluorideEstimation of plasma glucose
6. Acid citrate dextrose (ACD)Used as a preservative in blood bag (in blood banking)
Q-3-d) Define quality control (QC)? How can you maintain quality Control in a laboratory? (Jan-2021)

Quality control:

Quality control is the process to perform a test correctly and prevention of being a test done wrongly. 

Maintenance of quality control in the Laboratory:

This can be done in two ways:

  1. Internal Laboratory quality control.
  2.  External Laboratory quality control.

Internal quality control is performed by individual laboratories of their own Level in day to day activities to ensure the release of reliable test results. 

There are three phases of internal laboratory quality control. e.g-

  1.  Preanalytical : It includes patient preparation, sample collection and transportation to ensure a quality test report.
  2. Analytical and
  3. Post- analytical

Prospective phase of quality control: 

  • All the procedures should be documented. 
  • Laboratory equipments should be properly maintained 
  • Reagent, their expiry date and batch number should be checked.

Retrospective phase of quality control:

  • Regular testing of quality control products along with patient samples.
  • Comparison of quality control results in specific statistical limits. 
  • Computer aided cheek. The data entered daily can be analyzed by different quality control programs.
Q-3-e) Define and classify solution. How will you prepare 500ml of 10% Nacl solution?.(Jan-2021)


A solution is a homogenous mixture of two or more substances which has no definite chemical composition at a definite temperature and pressure.

 Example: Solution of sugar or salt in water.

Classification of solutions:


A. Qualitative solutions 

B. Quantitative solutions-

  1. Non-Standard-
  • Saturated solution 
  • Unsaturated solution 
  • Supersaturated solution
  1. Standard-
  • Normal solution 
  • Molar solution 
  • Molal solution 
  • Osmolar solution 
  • Percent solution:Weight-volume,Weight-weight, Volume-volume.

A. Qualitative solutions-

  1. Crystaloidal solution
  2. Colloidal solution-
  1. Emulsoid 
  2. Suspensoid

Preparation of 500 ml of 10% NaCl solution:

Method: Weight / volume

Apparatus required: 

  • Measuring cylinder
  • Chemical balance
  • Beaker
  • Stirrer
  • Reagent bottle
  • Pen
  • Paper 

Reagents required: NaCl, distilled water.

Calculation: 10% NaCl means –

100 ml NaCl solution contains 10g NaCI

1 ml NaCl solution contains 10/100 g NaCl

500 ml NaCl solution contains 10×500/100 = 50g NaCI


  • 50 g NaCI is weighed on an analytical balance. It is transferred to a beaker.
  • 300 ml of distilled water is added to it.
  • It is mixed by a stirrer.
  • Added more 200 ml distilled water with a measuring cylinder to make the final volume 500 ml.
  • It is mixed well and is stored in a clean and dry reagent bottle. 
  • It is labeled appropriately and stored at room temperature.
Q-4-a) Name the equipment and reagents used for Gram’s stain and AFB staining. (Jan-2021)

Gram’s stain equipment:

  1. Glass slide
  2. Cotton
  3. Platinum loop/Wire loop
  4. Spirit Lamp
  5. Culture media
  6. Staining rack
  7.  Microscope

Gram’s stain Reagent:

  1. 0.5% crystal violet or gentian violet or methylene violet
  2. Lugol’s iodine
  3. Alcohol / Acetone.
  4. Distilled water.
  5. 1 in 10 dilute carbol fuchsin solution.
  6. Cedar wood oil
  7. Normal saline

AFB stain equipment:

  • Glass slide
  • Cotton
  • Platinum loop/wire loop
  • Test tube with holder
  • Staining rack 
  • Spirit lamp 
  • Match
  • Microscope

AFB stain Reagents:

  • Carbol fuchsin Solution
  • 20%  H2So4
  • Methylene blue / Malachite green
  • Distilled water 
  • cedar wood oil.
Q-4-b) Describe SI unit and SI derived unit. (Jan-2021)

SI unit:

SI unit is the abbreviation of “Systeme International d’unites”. This means an international system of units for measurement. It is based on the metre-kilogram-second system and replaces the old systems. It overcomes the language barriers and permits exchange of health information within a country and between nations. 

  • SI unit comprises 7 base units (meter, kilogram, second, mole, ampere, kelvin, and candle); a set of 20 prefixes to the unit names and unit symbols. 

SI base units:

The seven SI base units are meter,kilogram, second, mole, ampere, kelvin and candle. These are called basic units because these are the building blocks of the system and all the other units are derived from them.

Table SI base units:

SI base unitsSymbolQuantity measured
molemolamount of substance
ampereAelectric current
candelacdluminous intensity

 SI derived units:

  • The units of measurement which consist of combinations of SI base units are called SI derived units.
  • 22 of the SI derived units have special names (for example – hertz, the SI unit of measurement of frequency, but the rest merely reflect their derivation : for example, the square metre (m²), the SI derived unit of area; and the kilogram per cubic metre (kg/m³), the SI derived unit of density.

Table : Named SI derived units:

Named SI derived units:SymbolQuantity measured
jouleJenergy, quantity of heat
voltVelectrical potential difference
degree celsius°Ctemperature
grayGyabsorbed dose (of ionizing radiation)
Q-4-c) Define first Aid.Name the contents of first Aid box. (Jan-2021)

First Aid:

Immediate emergency care given to an injured or suddenly ill patient before the arrival of a physician or transport to a hospital is called first aid.

Contents of First Aid Box:

  • First aid leaflet (clear instructions on how to apply emergency treatment) – 1 copy.
  • Sterile burn dressings – 3
  • Sterile dressing to cover wounds – 3 large and 3 medium.
  • Sterile cotton wool (25 gm) – 3 packets.
  • Triangular bandages – 12
  • Roll bandages -9 
  • Adhesive tape (1.5 cm and 2.5cm)
  • Sterile eye pads – 2 
  • Safety pins – 1 packet.
  • Scissors-1 pair. 
  • Disposable hand gloves – 2 pairs.
  • Liquid antiseptic – 50 ml bottle (Savlon/Dettol / Povisep)
  • Antiseptic cream – 1 tube.
  • Sodium bicarbonate powder.
  • Boric acid powder.
  • Torch light and extra battery.
  • Candle and match box.
Q-4-d) Define Catheterization. What are the principles, types and indications of catheterization? (Jan-2021)

The word catheterization means “introduction of a catheter”.


Catheterization is the process of introduction of rubber or plastic catheter through the urethra into the urinary bladder to drain out the urine.


Catheterization should be done using strict aseptic technique. Rubber catheter is best useful and it is introduced after lubrication to prevent friction, and no force is given. 

Intermittent catheterization is done by a plane catheter, urine drains from the tip via an opening and drains out through the lumen.

Indwelling catheterization is done by a Foley catheter which has a balloon and is inflated with distilled water after introduction; the balloon rests against the bladder outlet to anchor the catheter in place. One lumen of the catheter drains urine out.


1. Urethral catheterization:

  • Intermittent: Single use for a short period (5-10 min.) to drain the bladder. 
  • Indwelling: Short term and long term.

2. Cardiac catheterization

3. Arterial catheterization 

4. Ureteric catheterization

5. Suprapubic catheterization


1. Intermittent catheterization:

  • To relieve acute bladder distension immediately
  • To obtain a sterile urine specimen
  • To assess for residual urine after voiding
  • To instill a medication
  • For long-term management of the clients with incompetent bladders.

2. Indwelling catheterization:

  • Obstruction to urine outflow (e.g. due to prostatic enlargement)
  • In case of surgical operations on bladder, urethra and surrounding structures 
  • To prevent urethral obstruction from blood clots
  • To give continuous or intermittent bladder irrigation 
  • To record urine output accurately in critically ill or comatose patient
  • To manage inconsistency in unconscious patients 
  • During paralysis of the bladder (in spinal cord injuries).
Q-4-e) What are the common organisms  cause UTI? Give the basic steps of urine sample collection. (Jan-2021)

Common organisms  causing UTI:

  • Escherichia coli (E. coli)
  • Klebsiella species
  • Proteus species
  • Staphylococcus saprophyticus
  • Enterococcus species
  • Pseudomonas aeruginosa
  • Candida species
  • Adenovirus, BK virus and Cytomegalovirus.

Basic steps of urine sample collection for routine examination:

For routine examination, a fresh, cleanly collected midstream 15-20 ml urine sample is required. It is collected in a clean, dry, leak-proof, and sufficiently wide necked disposable container. 

The most satisfactory procedure is to label the container first and is given to the patient with appropriate directions as follows: 

  • Wash your hands.
  • Begin by cleaning the genitalia around the urethra with a pre-moistened cleaning wipe provided by the laboratory.
  • Strat to urinate a small amount into the toilet, and then collect the sample of “mid-stream” urine (15-20 ml) in a sterile screw-top container. (A mid-stream urine sample means one doesn’t collect the first or last part of urine that comes out.)
  • Avoid touching the inside of the container so you don’t transfer bacteria from your hands to the sample.
  • Screw the lid of the container shut. 
  • Wash your hands thoroughly.
Q-5-a) Write short notes on: Tourniquet test. (Jan-2021)

Tourniquet test:

Tourniquet test is part of the WHO algorithm for diagnosis of dengue fever. The test is also called Hess test or capillary fragility test.


Tourniquet test is simple. A blood pressure cuff is applied on the arm and inflated to the midpoint between the systolic and diastolic blood pressures for five minutes. The test is positive if there are more than 10 to 20 petechiae per square inch.

Tourniquet test test requirements: 

No specific machines or instruments are needed. Only Sphygmomanometer is needed.

Procedure of Tourniquet test:

  1. Apply the Sphygmomanometer cuff on the arm and inflate it to 80 mm Hg pressure.
  2. Keep this pressure for five minutes.
  3.  After five minutes, check the volar surface of the forearm for the appearance of petechiae at the antecubital fossa.
  4. If you found petechiae, count the petechiae in a 3cm² area.
  5.  If you found twenty (20) petechiae in this area, then the result is positive.

Factors affecting Tourniquet test:

There are two main factors that affect the Tourniquet test. 

  1. Time is an important factor. Sphygmomanometer cuff is applied for only 5 minutes. More than 5 minutes or less than 5 minutes can affect the result.
  2. Sphygmomanometer pressure is also an important factor. 80 mm Hg pressure should be applied. More than or less than 80 mm Hg pressure can alter the result.
Q-5-b) Write short notes on: autoclave. (Jan-2021)



Autoclaving is a method of sterilization by moist heat in which substances are sterilized at 121°C for 15 minutes.

Principle of autoclave:

1. At atmospheric pressure, water boils at 100°C.

2. With the rise of pressure, the boiling point of water also rises.

3. Steam under pressure unmixed with air has more temperature than that mixed with air.

4. Steam under pressure has more penetrating power. This is due to fact that, steam condenses to water on contact with materials. 

5. During condensation of steam to water, a large amount of latent heat is liberated, thus increasing the efficacy of sterilization.

Advantages of autoclave:

1. As it is moist heat, it has more penetrating power.

2. Pressure is applied, so effective under low temperature.

3. Liberation of latent heat occurs during condensation of steam. So, internal temperature increases.

4. Less time consuming.

5. No charring.

6. It is an efficient sporicidal procedure.

7. Dressing, apron, gloves, catheter, surgical instruments (except sharp cutting instruments) and natural & synthetic fibers can be sterilized by this method.

Disadvantages of autoclave:

1. Equipment is costly.

2. There is a chance of an explosion.

3. Plastic materials, fats, oils, powders etc. cannot be sterilized.

Q-5-c) Write short notes on: BP recording.(Jan-2021)


BP recording (Blood pressure recording):


  1. Sphygmomanometer (BP apparatus).
  2. A stethoscope.


  • Explain the procedure to the patient. Explain the sensation of cuff tightening on the arm and reassure the patient that this is safe.
  • Ask the patient to sit down or lying down and relax. The patient should have rested for 15 minutes before starting the procedure.
  • Ask the patient to loosen any tight clothing or remove long-sleeved garments so that it is possible to access the upper arm.


  • Place the uninflated cuff around the upper arm just above the elbow.The upper arm on which the BP cuff is to be tied must be at the level of the heart. 
  • Place two fingers slightly under-neath the uninflated cuff to locate the brachial artery, which is found along the inner side of the arm.
  • Place the stethoscope’s diaphragm over the brachial artery (in the bend of the elbow) and listen to the pulse.
  • Inflate the cuff – air is pumped in slowly until the high pressure stops blood flowing through the brachial artery. At this point, no pulse will be felt and no sound will be heard through the stethoscope. 
  • Start to deflate the cuff very slowly by opening the valve whilst watching the mercury level in the sphygmomanometer.Note the sphygmomanometer reading when the pulse reappears. This will be heard with a stethoscope as a tapping sound – record this reading as the Systolic pressure.
  • Deflate the cuff further and carefully listen to the tapping sound until the sounds disappear – record this reading as the Diastolic pressure.
  • Repeat the procedure if result is surprisingly high or low 
  • Record the BP (Blood pressure), first the systolic and then the diastolic as follows: 

The Systolic Pressure ———————- millimetres of mercury (mmHg)

The Diastolic Pressure ——————— millimetres of mercury (mmHg)

 A healthy heart will give a reading of approximately 120 systolic pressure and 80 diastolic pressure (120/80).

Q-5-d) Write short notes on: Incineration. (Jan -2021)


Incineration is a waste treatment process that involves the combustion of waste materials. It is a very effective method of reducing the volume and weight of waste, but it is also a source of greenhouse gas emissions and other pollutants.

Advantages of incineration:

  • Reduces the volume and weight of waste by up to 90%.
  • Destroys many harmful organic compounds, such as PCBs and pesticides.
  • Can be used to generate electricity.
  • Can be used to treat hazardous waste.

Disadvantages of incineration:

  • Produces air pollutants, such as dioxins and furans.
  • Can release heavy metals into the atmosphere.
  • Requires energy to operate.

Applications of incineration:

  • Municipal solid waste (MSW) disposal
  • Hazardous waste disposal
  • Medical waste disposal
  • Sewage sludge disposal
  • Animal waste disposal
Q-5-e)  write short notes on: Reagent strip. (Jan-2021)

Reagent Strip:

 It is the absorbance paper strip in which specific reagents are attached by which an antigen & antibody reacts and produces a colour band. 

Advantage of reagent strip:

  1. Reagent strip and easily available & cheap 
  2. By using reagent strip tests can be done within a short time.
  3. It is easy to carry to anywhere.
  4. Easy to perform a lab test.
  5. Anyone can do the test by using the proper method.

Disadvantage of reagent strip:

  1. Results are affected if the strip  comes in contact with moisture and heat.
  2. False positive results may be possible if the sample is not collected properly.
  3. Can not be used after a certain period (Date expires).
  4. It should be stored very carefully.
  5. Absolute results can not be achieved easily.


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