MLT Pathology Notes

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2021-07-13T12:52:00.005+05:30

thory part imbeded

How much fees of 2 years course for BSC laboratory?

2021-03-23T02:18:00.003+05:30

fees depends apon collage and university you want to take an admission different states have different fees structure here are some name of university where you can check the fees on university portal. the name listed below

How much fees of 2 years course for BSC laboratory?

Names of universities with their website link

Name of universities	Course provide by universities	Universities link
Rajasthan University of Health Sciences	B.Sc. Medical Lab Technology , Master of Science (M.Sc.)	click here
Rajasthan Para Medical Council.	Diploma of Medical Lab Technology (D.M.L.T.)	click here
Uttar Pradesh State Medical Faculty, India	B.Sc. Medical Lab Technology, Diploma of Medical Lab Technology (D.M.L.T.)	click here
king george medical university	B.Sc. Medical Lab Technology, Diploma of Medical Lab Technology (D.M.L.T.)	click here
Lovely Professional University, Jalandhar-Delhi, G.T. Road	bsc B.Sc. Medical Lab Technology,	click here
Para Medical Council of India	Diploma of Medical Lab Technology (D.M.L.T.)	click here
All India Institute of Medical Sciences AIIMS	B.Sc. Medical Lab Technology, , Master of Science (M.Sc.)	click here
Para Medical Council (Pb.) Mohali	B.Sc. Medical Lab Technology, Diploma of Medical Lab Technology (D.M.L.T.)	click here
H.N.B. Uttarakhand Medical Education University, Dehradun	B.Sc. Medical Lab Technology	click here
Singhania University	Certificate course, B.Sc. Medical Lab Technology, Diploma of Medical Lab Technology (D.M.L.T.)	click here
Mahatma Gandhi university of medical sciences &technology	Certificate course, B.Sc. Medical Lab Technology Master of Science (M.Sc.)	click here
ITM Group of Institutions.	B.Sc. Medical Lab Technology	click here
		....................................etc

you can choose any course as per your interest these university also provide other peramedical course

Morphology and Structure of Viruses

2020-05-23T19:44:00.002+05:30

Acid Fast Staining Technique and its Details Hindi

2020-05-20T17:13:00.001+05:30

Acid Fast Staining Technique and its Details Hindi

Method of bacteria examination in microbiology

2020-01-29T17:29:00.000+05:30

Microscopic Examination of Bacteria

Microscopic examination of stained or I unstained preparation of bacteria is usually one of the essential steps in the long process of isolating and identifying bacteria. Microscopy of stained smears helps to differentiate cellular constituents and render them more visible. Staining also helps to classify organisms by placing them in their separate groups, based on the staining reaction of the organism.

Method of bacteria examination in microbiology

WIRE LOOPS

Wire loop used in microbiology

The microbiological wire loops are used to make smears. They are made of platinum or nichrome wires.

The platinum wire used is actually a mixture of platinum (90%) and iridium (10 %). Platinum on its own is too soft to be of any use.
The nichrome wire is cheaper and more flexible. Disposable plastic loops are also available.

Wire loops are made in various sizes of between 1.5 mm and 3 mm in diameter with the handle or holder about 6-8 cm long (Fig. 3.1a).

The wire loops may be purchased commercially though making a wire loop is not very difficult

1. Wind the wire once round a rod of appropriate diameter.

2. With a pair of scissors, cut one arm of the wire wound around the rod, forming a loop.

3. Bend back the loop with a pair of forceps to centre it.

4. Insert into a metal wire loop holder.

Making a wire loop for bacterial examination

Making a Wet Preparation for Microscopy

1. On a clean microscope slide, place a drop of the material to be examined, e.g., urine, or mix a small portion of the specimen such as vaginal secretion in a drop of saline.

2. Carefully place a cover-slip over the preparation, making sure that there are no air bubbles trapped under the cover-slip.

3. Examine immediately. If there is going to be a delay in examining the preparation, it is recommended to seal the edges of the coverslip with nail varnish or petroleum jelly.

Hanging Drop Preparation

The hanging drop is a microscopic technique used to determine the motility of bacteria when suspended in a fluid.

True motility is when bacteria actively move from one position to another in a haphazard manner.

It should not be confused with Brownian movement which is the vibration caused by molecular bombardment, or the one-directional movement caused by convectional currents.

1. Make a ring of plasticine or vaseline about 2 cm in diameter on a clean slide.

2. Place a loopful of culture in the centre of a clean 22 mm square cover-slip.

3. Carefully press the ring of plasticine on to the cover-slip with the drop of culture in the centre of the ring and not touching the slide.

4. With a quick movement invert the slide so that the cover-slip is uppermost (Fig. 3.2).

Hanging drop preparation for bacteria examination

5. Examine under the microscope, first using the low power objective (16 mm) to focus on the edge of the 'drop', then observe motility with high-power (4 mm) objective.

6. At the end of the examination, discard the whole preparation into a jar of disinfectant and allow to soak to kill the microorganisms.

Note

1. A well-slide' with a depression in the centre can be used in place of the slide with a ring of plasticine. Remember to seal the cover-slip with vaseline or nail varnish.

2. With experience, one can use the ordinary wet preparation to determine motility microscopically.

PREPARATION OF SMEARS

Stained preparations are needed to examine microorganisms microscopically in order to study their morphology and observe their cellular constituents.

Smears (or tissue sections) are made and stained by anyone of the recognized staining methods.
Smears can be made from liquid or solid cultures or from clinical specimens.

Smears from Solid Media

1. Sterilize the wire loop in bunsen flame

2. Place one drop of sterile saline on a clean slide with the sterilized loop.

3. Re-sterilise the loop.

4. With the wire loop, pick a small portion of bacterial growth and emulsify it in the drop of saline and spread to give a thin homogeneous film or smear on the slide (Fig. 3.3).Sterilize the loop.

5. Allow the smear to dry in air, fix and stain.

Bacterial smear

Smears from Liquid Media

1. Sterilise wire loop in the bunsen flame.

2. Using aseptic technique, remove a loopful of the culture.

3. Place the culture on a clean slide and spread it with the loop to give a fairly thick film of culture. Sterilise the loop.

4. Allow the film to dry, fix and stain.

Note

1. Always allow the film to dry on its own in air without heating before fixing it. This is to prevent the smear from being washed off during staining.

2. From solid media the smear should be thin and from liquid media, it should be thick.

Smears From Clinical Specimens

Smears are made from original clinical specimens directly on the slide if it is a swab or with a loop if it is fluid.

Fixation of Bacterial Smears

The smear having been made and allowed to dry, is fixed by quickly passing it two or three times over a bunsen flame to a temperature of about 55 to 60 °C.

This is to coagulate the bacterial proteins which makes them adhere to the slide.

Fixation should be such that the bacterial morphology remains intact, preventing the smear from being washed off during staining. Overheating will lead to distortion of morphology.

STAINING OF BACTERIA

Dyes from which stains are made, are either natural or synthetic products. Most of the dyes used for bacterial smears are synthetic. The natural dyes are mostly used in histopathology. The synthetic dyes are all derivatives of benzene and are usually referred to as aniline dyes.

Stains are mostly salts, comprising a base and an acid. They are classified into acid, basic and neutral stains.

Basic stains are those in which the colouring substances are contained in the basic radical with the acid radical being colourless, while those stains in which the colouring substances are in the acidic radical and base components being colourless, are Acid stains. An aqueous mixture of some acid and basic dyes results in Neutral stains, with the colouring substances contained in both acid and base components.

The theory of staining reaction is not fully understood but it is generally believed to be a combination of chemical and physical reactions.
The bacterial cell which is rich in nucleic acid, has affinity for basic stains and so is stained by the basic stain.
The acid stain is useful for basic components and as a background stain to give a good contrast.

Mordant used in microbiology

Some organisms (or tissues) do not take up the stain except in the presence of a mordant--a substance that forms a link between the organism and the stain to bring about a staining reaction.

The mordant forms a 'lake with the dye which is capable of attaching itself firmly to the organism.
A popular mordant in bacteriology is the Lugol's iodine.
The mordant should not be confused with an accentuator which is a substance that greatly increases the staining power and selectivity of a stain.
It does not combine or form a lake with the dye.

Examination of stained smears All stained smears are examined with oil immersion objective (x 100).

Morphology And Structure Of Bacteria.

2020-01-26T18:24:00.001+05:30

MORPHOLOGY AND STRUCTURE OF BACTERIA

The classification of bacteria in routine use is 'artificial' and is based on some recognizable features and characteristics which have been arbitrarily selected. These features include:

Morphology
Staining reaction
Cultural requirements
Biochemical reactions
Antigenic structure
DNA base composition i.e. guanine: Cytosine ratio

Morphology And Structure Of Bacteria

Morphology and Anatomy of Bacteria

what is Bacteria

Bacteria are microscopic unicellular organisms. The unit of measurement of bacteria is the micrometer (um) and it is 1/1000 of a millimeter (.001 um). Morphological classification of bacteria is based on the following types of shapes of cells:

1. The spheroid or ovoid or coccus

2. Bacillus

3. Vibrio

4. Spirillum

5. Spirochaete

1. The spheroid or ovoid or coccus These groups of bacteria are popularly called cocci (plural of coccus). They measure about 0.5-1 um in diameter. Sometimes these cells are flattened or distorted to give a change in shape.

The bacteria multiply by binary fission. During multiplication, the daughter cell is attached to the parent cell but it gets detached before fission occurs again. The pairs of cocci seen are referred to as diplococci.
If the fission continues while they remain attached, chains of cocci are formed and are referred to as streptococci. If the division is not in one plain and clusters of cocci are formed randomly, they are known as staphylococci.
Tetrads (or tetracocci) are formed when the cocci remain in pairs for two consecutive divisions and form regular aggregates of four cocci.
When the terms Staphylococcus and Streptococcus are used as generic names, the first letter is a capital letter.

2. Bacillus This is a 'rod' shaped cell measuring about 1-10 um in length and 0.3-1.0 um in width. The bacilli (plural) or rods may remain attached after division and they are called streptobacilli; or they may be arranged at varying angles to one another due to incomplete separation after cell division, thus giving the appearance of Chinese lettering. This is characteristic of the genus Corynebacterium.

The morphology of some of these bacilli may be affected as a result of the formation of spores during unfavorable conditions. Some species contain these spores in the center with or without bulging and others may have them at terminal ends or towards one end.

3. Vibrio The vibrio is a short, comma-shaped rigid bacillus. It measures about 4 x 5um.

4. Spirillum The spirillum is a rigid spiral organism and it is variable in size, measuring approximately 4 x 0.2 um. It has a corkscrew (helical) shape.

5. Spirochaete This is a flexible spiral-shaped organism. It possesses an axial fiber around which the body is twisted in a helical fashion. It measures about 10–20 um in length and 0.2-0.4um in thickness.

Figure 2.1 shows the various bacterial shapes and arrangements.

Structure Of Bacterial Morphology

Anatomy of Bacteria

Morphology And Structure Of Bacteria

1. Flagella These are slender filaments that originate from the cytoplasm. They function as organs of motility. They are therefore seen only in organisms that are motile. They are proteins and have characteristic patterns of arrangement on the bacterial cell (Fig. 2.3). They are too thin to be seen in ordinary stained preparations but become visible only in silver impregnation preparation or in electron microscopy.

2. Pili Extruding from the cytoplasmic membrane is shorter and finer filaments than the flagella. These are the pili. Some of them are referred to as sex pili because of their role during conjugation when genes are transferred from one cell to another. Majority of them are referred to as common pili or fimbriae. These are thought to be the organs of adhesion that help bacteria to attach to the host cells.

3. Capsule This is a layer of loose slimy material that surrounds some bacterial cells. The capsules are composed mainly of polymers of polysaccharides or peptides. They resist phagocytosis and so their presence on a bacterium is associated with virulence. They are identified by negative staining due to their low affinity for simple stains.

Distribution of flagella

4. Cell Wall The cell wall is a prominent distinguishing feature of the bacterial cell with a rigidity and strength that protects the cellular contents. Chemically, the cell wall consists of peptidoglycan, a mucopeptide that is composed of alternating strands of N-acetyl-glucosamine and N-acetylmuramic acid residues, cross-linked with peptide subunits.

The peptidoglycan gives rigidity and shape to the organism. Structurally, the cell wall of a Gram-positive bacterium differs from that of a Gram-negative bacterium (Fig. 2.4). The Gram-positive cell wall is much more sturdy than the Gram-negative one due to its high content of peptidoglycan.
It has neither an outer membrane that contains specific proteins nor a periplasmic space, both of which are present in the Gram-negative cell. Teichoic acids are also part of the cell wall of Gram-positive bacteria.
The Gram-negative cell wall has a thin peptidoglycan layer with no teichoic acids. It has an outer membrane that consists of lipopolysaccharides. The lipopolysaccharide is toxic to humans. It is called endotoxin.

Bacterial cell wall

5. Cytoplasmic membrane This is a double-layered structure within the cell wall. It is composed of lipid and protein and acts as a semipermeable membrane through which nutrients pass into and out of the cell.

INTERNAL STRUCTURES

1. Mesosomes These are convoluted invaginations within the cytoplasmic membrane. They play an important role during cell division and in the secretion of certain enzymes.

2. Nuclear material Within the cytoplasmic membrane, the cell itself has the nucleus' which has no nuclear membrane and lacks a definite shape. It is a single circular strand of deoxyribonucleic acid (DNA) which acts as a 'nucleus (chromosome).

3. Ribosomes Ribosomes are located throughout the cytoplasm and are the sites of protein synthesis. They are important for conveying the genetic code of the nucleus into instructions in the manufacture of cellular components. They are composed of ribonucleic acid (RNA) and proteins.

4. Cytoplasmic inclusions These are seen in some bacteria and appear to be sources of reserved food for energy. For example, volutin (polymetaphosphate) granules associated with Corynebacteria.

5. Spores These are dense structures produced by the bacteria, e.g., the Bacillus and Clostridium groups, that enable them to survive adverse environmental conditions. They develop within and at the expense of the vegetative cell.

The spore comprises the chromosomal material surrounded by several layers of walls. The location and shape of the spore in the cell may be of diagnostic assistance, e.g, the spores of Clostridium tetani are terminal, and the diameter is greater than that of the parent cell so that they are characteristically of drum stick appearance.

The positions of spores are described as terminal, subterminal or central. Spores are resistant to heat, stains, desiccation, and disinfectants. Each spore germinates to produce a vegetative cell during favorable growth conditions.

Morphology And Structure Of Bacteria

Glucose Tolerance Test: Purpose, preparation, Procedure and Evaluation

2020-01-25T13:40:00.000+05:30

Glucose Tolerance Test (GTT)-its is also known as WHO Reference method

Preparing the Patient for GTT

Glucose tolerance test method
- (WHO Reference method)
- Results
Evaluation of GTT results

Glucose Tolerance Test (GTT)

This is also usually referred to as oral glucose tolerance test (OGTT). Glucose tolerance test (GTT) measures the ability of the body to tolerate a measured dose of glucose. The rate of glucose absorption and response of insulin mainly determines the extent of glucose tolerance as shown by the changes in the level of blood glucose.

When there is rise in blood glucose, insulin is released from the pancreas to lower the glucose level. Tolerance is reduced when insulin is absent or insufficient.
A rise in blood glucose value usually occurs after having a meal containing carbohydrates.

Therefore, the response to carbohydrate level depends on the previous carbohydrate diet and on the amount ingested.
The effect of ingested carbohydrate is the basis of the glucose tolerance test.

It simply detects abnormalities in the carbohydrate metabolism and in cases where glycosuria has been found.

The oral glucose tolerance test is performed in order to screen

Patients having glycosuria with no apparent symptoms of diabetes and with normal fasting and post-prandial blood glucose levels.
Patients showing symptoms of diabetes with no glycosuria and normal fasting level of blood glucose.
Persons with family history of diabetes but with no overt diabetes.
Patients having glycosuria in conjunction with pregnancy, thyrotoxicosis, liver disease or infection.
Patients showing evidence of neuropathies and retinopathies of unconfirmed origin.

Preparing the Patient for GTT

(i) Place the patient on a diet containing not less than 150 g of carbohydrate for about three days before the test.

(ii) The patient should not eat anything after supper and no breakfast is given on the day of the test. No drink, except ordinary plain water should be given. For children, the time the food is denied is as follows:

Infants less than 4 months = 4 hours fast
Infants age 4 to 6 months = 6 hours fast
Children aged 6 to 24 months = 8 hours fast.

(iii) Patient should not be subjected to excessive exercise like walking long distance, excitement or fear, because all these can lead to a reduction in glucose tolerance.

(iv) The test is preferably done in the morning and ideally, when the patient is not suffering from any other disease.

Glucose tolerance test method (WHO Reference method)

Collect a fasting sample for blood glucose and collect a urine sample from the patient.

Give the patient 75 g glucose dissolved in 250 to 350 ml of water to drink. For children 1.75 g per kg body weight to a maximum of 75 g is given.

Alternatively, a 105 ml of lemon flavoured glucose syrup called Hycal (Beecham research laboratories), diluted to 250 to 350 ml with water, can be given.

This dose applies to adults only. For children, the pharmacy will supply the appropriate dose on request.

After one hour, take a sample for blood glucose and also collect a urine sample.

After 2 hours take a further sample for blood glucose and collect the final urine sample.
Estimate the blood glucose levels of each specimen, and test the urines for thepresence of glucose.

Results

Normal response: The fasting blood glucose should be less than 5.5 mmol/L and the two hour level less than 7.0 mmol/L.

Diabetic response: The fasting levels of glucose should be greater than 7.0 mmol/L and the two hour level should be greater than 10.0 mmol/L.

Evaluation of GTT results

Evaluation of GTT results
Method 1

Healthy individual
Fasting	<5.5 mmol/L
1 hour specimen :	< 10.0 mmol/L
2 hour specimen :	<7.0 mmol/L
Diabetic individual
Fasting:	7.8 mmol/L
1 hour specimen :	11.1 mmol/L
2 hour specimen :	11.1 mmol/L
Impaired glucose
tolerance fasting :	7.8 mmol/L
1 hour specimen	11.1mmol/L
2 hour specimen :	7.9-11.0 mmol/L

Screening Tests for Diabetes Mellitus.

2020-01-24T13:18:00.000+05:30

Screening Tests for Diabetes Mellitus.

The screening tests for diabetes include urine and blood glucose examinations.

1. Urine glucose

In determining the presence of glucose in urine, it should be remembered that "true glucose" must exceed 10 mmol/L (180 mg/ dl) before glucose can pass into the urine (Renal threshold).

The renal threshold is, however, elevated in diabetic kidney.

Also, the renal threshold increases with age. In some elderly patients no.glycosuria may be present even with serum glucose level as high as 11.1 mmol/L (200 mg/dl).

Methods of screening for urine glucose are discussed later in the URINE ANALYSIS.

2. Fasting blood sugar

It is preferable to use plasma for this test. Glucose levels in excess of 6.6 mmol/L (120 mg/dl) is suggestive of diabetes mellitus; and values between 6.0 to 6.6 mmol (110 to 120 mg/dl) are doubtful and should be confirmed by performing the glucose tolerance test.

It is important to remember that conditions such as emotional hyperglycaemia resulting from secretion of epinephrine: general brain damage such as skull

3. Two-hour post-prandial (pp) blood glucose

Two hours after the patient has broken fast by being fed on adequate carbohydrate meal, a single blood sample is collected and analysed.

Glucose level in excess of 10 mmol/L (180 mg/dl) is highly suggestive of diabetes mellitus and should be confirmed with a GTT.

A single two-hour pp glucose level has the limitations due to

(i) Delayed peak level due to slow absorption

(ii) Early hyperglycaemia due to rapid absorption

(iii) Quick fall in concentration of blood glucose level due to the release of insulin.

(iv) Wrong specimen collection timing.

4. Glucose Tolerance Test (GTT)

This is also usually referred to as oral glucose tolerance test (OGTT). Glucose tolerance test (GTT) measures the ability of the body to tolerate a measured dose of glucose.

The rate of glucose absorption and response of insulin mainly determines the extent of glucose tolerance as shown by the changes in the level of blood glucose.

Screening Tests for Diabetes Mellitus

Method 2

One can prepare a curve of blood glucose level against minutes (time) for the GTT. Compare it with a normal curve (Fig. 3.3).

Method 3

Wilkerson point system

Wilkerson point system
Time	mmol/L of glucose	Point
Fasting	7.0 or more	1.00
1 hour	10.0 or more	0.5
2 hour.	8.0 or more	0.5
3 hour	7.0 or more	1.00

The GTT is diagnostic of diabetes mellitus with this point system, if

Two or more points are scored with up to 3 hour sample.
One or more points are scored with up to 2 hour sample.