FIG. : General prohibition

FIG. : General laboratory

12 Concise Book of Medical Laboratory Technology: Methods and Interpretations 5. Broken glass

6. Contamination by infected material

7. Electric shock.

A suggested list of first aid equipment is given later in

the chapter. The items should be readily available in the

laboratory. They must not be kept in a locked cupboard.

First Aid in Laboratory Accidents

Acid Burns

Nitric, sulfuric, hydrochloric and trichloroacetic acids.

In all cases: Wash immediately with large quantities of

water.

Acid Splashes on the Skin

a. Wash thoroughly and repeatedly with water.

b. Bathe the affected skin with cotton wool soaked in 5%

aqueous sodium carbonate.

Acid Splashes in the Eye

a. Wash the eye immediately with large quantities of

water sprayed from a wash bottle or rubber bulb.

Squirt the water into the corner of the eye near the nose

(Figs 1.4 and 1.5).

b. After washing, put 4 drops of 2% aqueous sodium

bicarbonate into the eye.

c. Refer the patient to a physician. Continue to apply

bicarbonate solution to the eye while waiting for the

doctor. Alternatively, hold the eye under the running

tap.

Swallowing Acids

Accidental swallowing while using a pipette:

a. Call a physician.

b. Make the patient drink some 5% soap solution

immediately. Alternatively, give him two whites of egg

mixed with 500 mL of water or milk. If neither of these

is available, he should drink ordinary water.

c. Make him gargle with the soap solution.

d. Give him 3 or 4 glasses of ordinary water.

e. If the lips and tongue are burned by the acid:

• Rinse thoroughly with water

• Bathe with 2% aqueous sodium bicarbonate.

Alkali Burns

Sodium, potassium and ammonium hydroxide.

In all cases: Wash immediately with large quantities of water.

Important: Alkali burns are as serious as, and often more

serious than, acid burns.

Alkali Splashes on the Skin

a. Wash thoroughly and repeatedly with water.

b. Bathe the affected skin with cotton soaked in 5% acetic

acid (or undiluted vinegar).

Alkali Splashes in the Eye

a. Wash immediately with large quantities of water

sprayed from a wash bottle or rubber bulb. Squirt the

water into the corner of the eye near the nose.

b. After washing with water, wash the eye with a saturated

solution of boric acid (apply drops repeatedly).

c. Refer the patient to a physician at once.

Swallowing Alkalis

Accidental swallowing while using a pipette:

a. Send for a physician.

b. Make the patient drink at once:

FIG. 1.4: Eye washing upright

FIG. 1.5: Eye wash lying

Laboratory 13

• A 5% solution of acetic acid or lemon juice or

dilute vinegar (1 part vinegar to 3 parts water).

c. Make him gargle with the same acid solution.

d. Give him 3 or 4 glasses of ordinary water.

e. If the lips and tongue are burned by the alkali:

• Rinse thoroughly with water

• Bathe with 5% acetic acid.

Poisoning

This can be caused by:

¾ Inhaling toxic vapors or gases (e.g. chloroform)

¾ Accidental swallowing while pipetting a poisonous

solution.

In all cases

a. Send for a physician or qualified nurse, specifying the

toxic substance involved

b. Place the victim in the open air while waiting for the

physician.

 

extinguisher

Flammable liquids

and gases, electrical fire

—

Dry powder As above —

Foam Flammable liquids —

Halon spray All kinds of fires —

8 Concise Book of Medical Laboratory Technology: Methods and Interpretations ¾ Biological safety cabinets: Prevent dangers arising out

of aerosols and splatters

¾ Splatter shields: Provide protection from splatter of

specimen and chemicals

¾ Pipetting aids (teat or electromechanical devices).

Prevent from hazards arising out of mouth pipetting

¾ Goggles: Protect eyes from impacts and splashes

¾ Face shields: Protect the face from impacts and

splashes.

Safety with Chemicals/Reagents

Excepting just a couple of reagents, almost all chemicals/

reagents used even in the most basic laboratory are lethal

poisons if consumed by anyone. Even if they are splashed

on the skin/eye, they can cause irreversible damage. There

is an appropriate way of handling and storage of hazardous

chemicals to avoid injury and damage to self and others.

In our country (and other tropical nations), excessive heat

can decompose many chemicals, cause explosions, or lead

to the formation of toxic fumes.

Labeling of Hazardous Reagents/Chemicals

At appropriate places, display the prohibition signs; and

on all dangerous reagents or chemicals, stick Hazard

warning symbols. In the following pages, important signs

and symbols as related to safety in the laboratory are given.

Incompatible Chemicals

Fair number of common laboratory chemicals react

dangerously if they come in contact with specific chemicals.

Ensure that you keep such chemicals away from each other.

A few examples are listed below:

Acids

¾ Acetic acid with chromic acid, nitric acid, hydroxyl

compounds, ethylene glycol, peroxides and permanganates

¾ Chromic acid—with acetic acid, alcohol, glycerol and

other flammable liquids

¾ Sulfuric acid—with chlorates, perchlorates, permanganates and water.

Vaporizing Substances

¾ Acetone—with sulfuric acid and nitric acid

¾ Flammable liquids—with chromic acid, hydrogen

peroxide, nitric acid, ammonium nitrate and halogens.

Others

¾ Alkali metals, e.g. calcium, potassium, sodium (these

form hydroxides on coming in contact with water) and

with other chlorinated hydrocarbons

¾ Chlorine—with ammonia, hydrogen, benzene and

other finely divided metals

¾ Copper—with azides, hydrogen peroxide and acetylene

¾ Cyanides—with all acids and alkalies

¾ Hydrogen peroxide—with copper, iron, chromium and

most other metals

¾ Iodine—with acetylene and ammonia

¾ Sodium azide—with lead, copper and other metals.

Flammable Chemicals

These include ether, xylene, toluene, methanol, ethanol,

glacial acetic acid, acetic acid, acetone, acetic anhydride,

alcoholic Romanowsky stains and acid alcohol, etc.

Storage

These should be stored in a fire-proof metal box at ground

level, preferably in a cool store. A container well lined with

tin foil can also be used. Store only small quantities of such

solvents on the shelves.

Safe Use

Ensure that there is no open flame nearby while opening a

bottle containing flammable solvent. Nearest flame should

be at least 10 feet away. Never heat a flammable liquid over

 

cover your mouth and nose with a damp cloth to filter

out some of the harmful fumes

¾ Inform firefighting department of your area if you

feel the fire can go out of hand. Medium to large fires

should be reported irrespective of your preparedness to

handle them.

Laboratory Equipment (Table 1.1)

¾ Use all laboratory equipment as per manufacturer’s

recommendation

¾ Any instrument with moving parts, such as a centrifuge,

must be operated with a special regard for safety. Latch,

the lid before turning it on. On turning it off, do not

open the lid before it has come to a complete stop

¾ Autoclaves present special hazards. Strictly adhere to

manufacturer’s instruction to prevent explosions and

burns. Use insulated gloves while removing hot items

from the autoclave.

Glassware

¾ Use glassware that is free of chips and cracks. Damaged

glassware is weakened and may break, resulting in

injury

¾ Broken glass should be cleaned with a brush and

dustpan and not with bare hands

¾ Glass should not be discarded into regular trashcans,

but into rigid cardboard or plastic containers

¾ Wherever possible, replace glassware with plasticware.

Equipment Related Hazards

¾ Hypodermic needles: Accidental inoculation, aerosol

or spillage

¾ Centrifuges: Aerosols, splashing and tube breakages

¾ Culture stirrers, shakers, agitators: Aerosols, splashing

and spillage

¾ Refrigeration: If flammable chemicals are stored within

them, the light switches, thermostats, etc. can provide

sparks to ignite them

¾ Water baths: Provide ground for microorganismal

growth

(The risk of acquiring hepatitis B from a needle stick is

30%, hepatitis C is 2 to 10% and HIV is 0.3%).

Equipment/Materials Employed to Eliminate/Reduce

Hazards

¾ Laboratory apron: Assists in diminishing skin contacts

to a certain extent

TABLE 1.1: Fire fighting equipment

Fire fighting material Used for Contraindicated for

Fire blanket Clothing fire,

G small blaze

Electrical fires, flammable liquids, a small

blaze burning metals,

alkali metal

Water Paper, wood, fabric Electrical fires, flammable liquids, burning metal, alkali metal

CO2 fire

 

Stores

¾ Every bottle/container should be labeled. Affix the

hazard intensity on the bottle or the container

¾ Ensure in every possible way that the containers cannot

under any circumstances fall or spill. This can be done

by placing the most dangerous chemical at the bottom

or at the floor level

¾ Proper ventilation should be ensured in storage

zones that house flammable chemicals. Keep fire

extinguishing equipment handy. Post “No smoking”

signs that are clearly visible. Make sure that the place

remains free from pests.

Staff Safety and Facilities

The most important asset of any institution is the manpower that works for it. It holds true for laboratories

too. Absence of staff due to morbidity or mortality can

stifle your working capacity, capability and reputation.

Provide adequate facilities to your team. (Designate a

room or space meant exclusively for retiring or resting and

consuming foodstuffs).

¾ Hot and cold running water with soap and disinfectants

should always be provided. Clean hand towels should

be replaced daily

¾ A clean toilet for use by staff members is mandatory as

are the changing rooms. If possible, separate units for

male and female members should be provided

¾ Biomedical wastes and non-biomedical wastes should

be discarded properly and safely. Chemical treatment

of liquid wastes and incineration of solid wastes should

not be overlooked. Wastes handled properly ensures

good health of your working team

¾ Designate a room or space meant exclusively for

retiring or resting and consuming foodstuffs. Under no

circumstances, laboratorians should eat or drink on

their workbenches. Provide safe drinking water to all

¾ Each room/cabin must have a first-aid box kept at an

identified place that is easily accessible. Every person

working in the laboratory must be aware of all hazards

that exist and must also know about the remedial

measures that should be taken if something happens.

What can be managed in house should be managed,

when required, assistance of other specialists must be

taken. Contact numbers of such institutions/specialists

must be displayed prominently

¾ All members of your team must be immunized as

relevant to the laboratory work. Make sure no single

person works alone in a room or cabin. Two compatible

persons should work together always.

Basic Laboratory Safety

¾ Use only certified safe equipment in the laboratory

¾ Decontaminate all equipment regularly and before

their servicing or maintenance, use appropriate

disinfectants correctly

¾ As far as possible, use disposable plasticware to

avoid contamination (chemical, biological, etc.) and

breakages with ensuing dangers

¾ Regularly test and service biological safety cabinets and

fume cupboards.

 

Appropriate safety measures taken by you will go a long

way in enhancing productivity.

6 Concise Book of Medical Laboratory Technology: Methods and Interpretations As a rule, the place for receiving or withdrawing the

specimens should be separate from the working compartment. To avoid specimen mixing (hazardous), each sample

should be carefully labeled. The label should clearly

mention the alloted specimen number, the date and time

of receipt of specimen, the investigations to be done and

most important the name of the patient.

Both, the clinical and the paraclinical workers are

equally at risk of acquiring transmissible diseases through

the patient or through the test samples. The risk of these

can be lessened by taking appropriate vaccinations. In

addition, one should attend to one’s general hygiene and

prevent fomite transmission of any infectious disease.

Disinfect the working benches and as far as possible

autoclave (or chemically disinfect) various glassware used

in the laboratory. Use a rubber teat for sucking/filling

the pipettes. To avoid strain on the eyes, keep both eyes

open while doing microscopic work. Before leaving the

laboratory, one should thoroughly wash one’s hands with

soap and water, and then rinse them well in a disinfectant

lotion.

CODE OF CONDUCT FOR MEDICAL

LABORATORY PERSONNEL

1. Place the well-being and service of the sick above your

own interests.

2. Be loyal to your medical laboratory profession by

maintaining high standards of work and strive to

improve your professional knowledge.

3. Work scientifically and with complete honesty.

4. Do not misuse your professional skills or knowledge

for personal gain.

5. Never take anything from your place of work that does

not belong to you.

6. Do not disclose to a patient or any unauthorized

person the result of your investigations.

7. Treat with utmost confidentiality and personal

information that you may learn about a patient.

8. Respect and work in harmony with the other members

of your hospital staff or health center team.

9. Be at all times courteous, patient, and considerate to

the sick and their relations.

10. Promote health care and the prevention and control

of disease.

11. Follow safety procedures and know how to apply first

aid.

12. Do not drink alcohol during laboratory working hours

or when on emergency stand-by.

13. Use equipment and laboratory-ware correctly and with

care.

14. Do not waste reagents or other laboratory supplies.

15. Fulfil reliably and completely the terms and conditions

of your employment.

Always remember that you can be a patient tomorrow.

Treat others as you would want them to treat you.

ACCIDENTS

Safety Measures in the Laboratory

You must remain alert and cautious while working in

the laboratory. You must know that careless handling

of reagents, glassware or specimens to be tested in the

laboratory can cause serious injury and is dangerous to

life.

Hazards in the Clinical Laboratory

Clinical laboratory workers may encounter three types of

hazards:

 

Provisions and Precautions

Every working room or cabin should have adequately

spaced provision of water, electricity, gas, sinks lighting

and exhausts. All aspects, whether plumbing, electrical

systems or gas connection must pass through regular

inspections and a log book should be maintained of such

preventive exercises. Preventive maintenance should be

carried out by knowledgeable and qualified persons.

Fire Prevention

¾ Install appropriate fire extinguishing system and timely

testing of such a system be conducted at regular intervals

¾ Color code and place firefighting equipment at an easily

visible and reachable location. Check the working

capability of all such systems at regular intervals

¾ Provide adequate ventilation in zones where flammable

chemicals are used. Before these substances reach

combustible or explosive concentration, they should

be removed by mechanical exhausts FIG.1.3: A typical large/complete laboratory plan

FIG. 1.2: A typical small laboratory

Sero-immunology

ELISA’s, PCRs, drugs,

Cancer markers

Biochemistry Microbiology

Pathologist’s chamber Collection of

specimens and

report delivery

Hematology +

Clinical pathology

Histopathology

Cytopathology

Toilet

Laboratory 5

¾ Post “No-smoking” signs in zones where smoking can

be hazardous

¾ Lastly, mark clearly the emergency exit points. Keep the

emergency exit route free from obstructions.

Electrical Installations

¾ Hire a proper, qualified electrical engineer and explain

to him the purpose of the premises being taken. As far

as possible, all points where sparks can be generated

should be kept out of room/cabins where explosive

chemicals are likely to be used

¾ Use earthing everywhere and install fire-resistant

cables in the laboratory

¾ Employ only certified products

¾ Use one electrical socket for a single device or machine.

Overloading is usually the cause of accidents.

Liquefied and Compressed Gases

¾ Color code and identify each gas container. Check their

valves regularly

¾ Keep all such cylinders away from sources of heat and

electrical sparks

¾ When not in use, replace protection/safety caps back

on the cylinder mouths.

Chemicals and Radioactive Substances

¾ Label all bottles with proper names of contents and

affix warning signs and symbols as applicable to them

¾ Clearly display the warning charts (both chemical and

radioactive) next to such containers. All staff members

working in such areas should be well trained to handle

accidents of any kind that can happen

¾ A stringent record of stocks should be maintained of

all persons and radioactive substances being used in

the laboratory. A bottle lost or stolen is invitation to

problem.

 

e-mail, etc.

In the United States of America, these laboratories

though classified differently (with a few differences) are

covered under the Clinical Laboratory Improvement Act

(CLIA) of 1988.

LABORATORY SET-UP

Unless the laboratory is hygienic and provides necessary

physical and operative comfort, it would be wrong to

expect perfect results. To get perfect results, one has to

provide a perfect set-up for people to work in.

Laboratory Building and Space

Ample working space is absolutely essential. For smaller

laboratories up to 25 square meters (Fig. 1.2), the working

platforms can be arranged along the walls while the central

area is kept free for movement.

4 Concise Book of Medical Laboratory Technology: Methods and Interpretations For larger areas, partitions can be made which would

create separate spaces for different sections (Fig. 1.3).

The chief pathologist must have casual access to all subunits of the laboratory. If possible, he should be able to

directly see into the cabins either through glass windows

or through closed circuit cameras. In the cabins again, the

central region should be kept free and benches be placed

against the walls and away from the doors.

¾ Hygiene is of utmost importance. The whole facility

should be absolutely clean, uncrowded and devoid of

any hindrances to movement of men and materials.

Never, should a chance arise where two people would

clash or contaminated material would be spilt all over

¾ Scratch proof matt finish vitrified floor (slip resistant)

should be provided. The walls should preferably have

white ceramic tiles. Such provisions are resistant to

chemicals and disinfectants

¾ All benches should be preferably 2½ feet high and those

to be used while standing should be at least 3 feet high.

The bench surfaces should be solvent and acid proof.

Every laboratory and/or its section must have at least

one sink and one hand wash basin. The hand wash basin

should not be used for any other purpose, the sink can

be utilized for laboratory purposes like washing off stains

from slides or washing glassware or discharging noncontaminated laboratory refuse.

Physical Aspects of a Laboratory

¾ The ambient temperature should be within the comfort

zone of a human body. It should between 21 and 27°C.

If the laboratory is in a cold zone, it must have heating

provision, and conversely, if it is in a hot zone, it must

have cooling or air conditioning. The environment

control appliances like air conditioners or heaters must

not directly discharge air at the working bench zone

¾ A good exhaust system is a must for all laboratories.

This removes dirty air (aerosols), which may at times

be foul smelling. The sample collection zone too, must

have excellent exhaust provision

¾ Adequate ventilation is also essential but without

strong currents of air

¾ Lighting should be more than adequate and places

where very delicate or fine processes are being

conducted should have additional lighting provision.

As far as possible, do not use excessive heat producing

bulbs and lamps. The new CFLs are ideal

¾ Windows that are exposed to bright sunlight can be

internally fitted with reflective films or blinds

¾ There should be sufficient running water for the

laboratory and all must have sufficient number of sinks

and hand wash basins

¾ As most machines consume a lot of electricity, sufficient

power load (a little in excess) must be available to the

laboratory

 

physician chambers nowadays, so that clinicians may

obtain basic inputs right in their own premises. These

primary laboratories may provide the following simple

investigations:

¾ Hemograms (hemoglobin estimation, total and

differential counts, erythrocyte sedimentation rate and

packed cell volume with basic peripheral smear study

including the reporting of hemoparasites)

¾ Routine and microscopic studies of urine and stool.

Routine examination also entails chemical examination either by laborious and time-consuming old

chemical methods or by new generation dipstick

tests. These may include tests for glucose, bilirubin,

ketones, hemoglobin, leukocytes, pH, nitrites, protein,

urobilinogen and specific gravity in case of urine. For

stool samples, reducing substances, pH and occult

blood may be performed. Basic spot/latex/device tests

(e.g. pregnancy test) may be conducted.

Secondary Laboratory

These are laboratories that assist a clinician to confirm a

clinical suspicion or establish a diagnosis. Therapy and

prognosis monitoring can also be provided from these

laboratories. Such laboratories are staffed by qualified

personnel who are trained and experienced to perform the

tests. They also have a perfect knowledge of the equipment

and machines they use. They should be aware of quality

control essentials and be well versed with interpretational

aspects of the reports generated by their laboratories. In

addition to what has been mentioned under primary

laboratories, secondary laboratories also perform:

¾ Routine immunohematological tests.

¾ Routine examination of all body fluids, e.g. semen,

cerebrospinal fluid (CSF), sputum, etc.

¾ Routine bacteriologic studies including stains, cultures

and antibiograms. Routine mycological investigations

would include—primary cultures, isolation and identification techniques along with microscopic evaluation.

¾ Routine immunoserological tests. These can include

tests like Widal, STS, ELISA or strip or device tests HIV I

 

Breast Cancer Diagnostics 1002

Prostate Cancer Diagnostics 1003

Hematopathology 1004

Colorectal Diagnostics 1004

Lung Cancer Diagnostic Solutions 1005

Benchmark Ihc/Ish Platform 1007

Benchmark System Features 1007

Digital Pathology 1008

Vantage Workflow Solution 1009

Consultancy Services 1011

Sequencing Solutions 1013

Genome Sequencer Flx+ System 1013

Gs Junior System 1014

Nimblegen Sequence Capture 1015

Roche Dialog 1017

Appendix 1019

Index 1033

INTRODUCTION

The definition of health includes a state of complete and

perfect physical, mental, social and spiritual well-being

and not just the absence of disease or infirmity and good

health is a fundamental right of every living human

being on earth. However, modern world, though, has to

an extent eliminated infectious diseases. But the focus

has now shifted to lifestyle diseases. Pollution of every

nature too has taken its toll. About half a century back,

the predominant diseases used to be infective ones but

now you may find individuals in mid-twenties waiting

for their turn for open heart surgeries. Also, modern

medicine has increased the longevity of life accompanied

by attendant geriatric diseases like Alzheimer’s disease

and malignancies. The polluted and toxic world has

not spared the fetuses in utero and neonates. A new

face of disease has emerged, diseases like HIV-AIDS

and severe acute respiratory syndrome (SARS), are new

entrants in the long list of infective diseases. We may

have eradicated smallpox but tuberculosis and malaria

have raised their heads with a vengeance. So, do what

you might. Some forms of disease, mild or severe will

strike every human being living. On getting sick, the

patient first comes in contact with a clinician—medical

or surgical. The clinician gives a patient hearing (if the

patient is conscious) to his problems and symptoms and

also takes note of various signs, which he sees or elicits.

Sometimes, he may immediately arrive at a diagnosis

and may under emergency circumstances institute

treatment at first instances. In most cases, however, he

will have a differential diagnosis in mind and to arrive

at a specific diagnosis he usually orders for a battery of

tests.

 

Laboratory

C H A P T E R

2 Concise Book of Medical Laboratory Technology: Methods and Interpretations

Clinical laboratory investigations nowadays are being

utilized as future predictors. On getting warning signals,

one can take necessary corrective measures (lifestyle and/

or dietary) and can prevent diseases from striking or at

least deferring or postponing their arrival.

HELP! AND YOU DID AND YOU ALWAYS WILL. When

a clinician is lost, you shall show him the way in the best

possible way, you lead him to a diagnosis and let him

do his job thereafter. He may come back to you later to

determine that his efforts have been fruitful.

The following pages within the covers of this book will show

you the right path on how to be an excellent laboratorian.

Do your best in serving mankind. As you yourself may be

a patient tomorrow. This book shall also serve you well by

providing interpretation of the results obtained by you.

This book shall be true to its title “Concise Book of Medical

Laboratory Technology: Methods and Interpretations”.

While physiology is the study of essentially normal

structures and functions of a body, pathology deals with

the study of a diseased organ or system of the body, its abnormal functions, their mode of origin, their progress to

recovery or otherwise. All these studies come under the

ambit of a clinical pathology laboratory. A clinical laboratory has further sub-branches such as: hematology, biochemistry, seroimmunology, microbiology, cytogenetics,

histopathology, cytopathology, blood banking and last but

not least—clinical microscopy.

A clinical laboratory can be manned by a qualified

doctor specializing in clinical pathology, biochemistry,

immunology, blood banking, histopathology, cytopathology,

hematology, microbiology or cytogenetics. The pathologist

is usually assisted by laboratory technicians or technologists

(they are also qualified for the job) and lastly the cleaning

and documentation staff. Only by collective efforts of

the individuals mentioned above, a proper report can be

generated. Be grateful to the clinician for having faith in you

and give back nothing except an accurate and correct timely

report. A delayed report may at times be too late. The patient

may have lost his life by then. A timely correct report is the

essence of running a good laboratory.

The cycle of health-disease with all intermediaries is

given in Figure 1.1. Just as there are primary, secondary

and tertiary health centers, there are also the primary,

secondary and tertiary laboratories too. In India, there are

no specific guidelines as to what or how much they can

do and overlapping can occur. A superior laboratory may

perform all functions of an inferior laboratory too.

Primary Laboratory

In rural setups, for instance, a primary laboratory may

provide only the basic investigations. These investigations

are simple to perform and do not involve expensive

machinery usage. Such laboratories are also attached to

FIG. 1.1: Health-disease-health cycle

Laboratory 3