MICROBI PRACTICAL
OLOGY MANUAL
S.No Major Practicals 1 Gram’s staining of curd/idly batte
2 Identification of the fungus(Asp wet mount using LPCB.
3 Blood grouping 4 Blood staining 5 Test for catalase 6 Widal test (slide test) 7 Demonstration of rhizobium from
S.No Spotters II A) Specimen
1 Root nodules of leguminous plant
2 Tikka leaf spot of groundnut plan
3 Mushroom 4 Sand fly 5 Ascaris
II B) Slide
6 Cyst of Entamoeba histolytica 7 Penicillium species 8 Microfilariae
9 Egg of Ascaris lumbricoides 10 Heterocysts of Nostoc 11 Acid fast bacilli
II C) Spotter
12 Antibiotic sensitivity plate set up 13 Sugar fermentation tube showin 14 Agarose gel electrophoresis appa 15 Spoiled food
Std XII Microbiolog
. Page. No r/yeast 284
ergillus/Mucor/Rhizopus) by 285
287
288
290
292
root nodules and its isolation 294
Page. No
297
t 297
298
298
299
299
300
300
301 301
302
by Kirby Bauer technique 302
g acid and gas production 303
ratus. 303
304
y Practical Manual
| S.No | Major Practicals . | Page. No |
|---|---|---|
| 1 | Gra m’s s t ainin g o f c ur d/id ly b atter/y e ast | 284 |
| 2 | Identification of the fungus(Aspergillus/Mucor/Rhizopus) by wet mount using LPCB. | 285 |
| 3 | Blood grouping | 287 |
| 4 | Blood staining | 288 |
| 5 | Test for catalase | 290 |
| 6 | Widal test (slide test) | 292 |
| 7 | D em onst ra t io n o f rhizo bium f rom ro ot no du les and its is ol at io n | 294 |
| S.No | Spotters | Page. No |
| II A) S p e cime n | ||
| 1 | R o ot n o du les o f legumin ous p l ant | 297 |
| 2 | Ti k ka le af s p ot o f g roun dn ut p l ant | 297 |
| 3 | Mushroom | 298 |
| 4 | Sand fly | 298 |
| 5 | Ascaris | 299 |
| II B) S li d e | ||
| 6 | Cyst of Entamoeba histolytica | 299 |
| 7 | Penicillium species | 300 |
| 8 | Microfilariae | 300 |
| 9 | Egg of Ascaris lumbricoides | 301 |
| 10 | Heterocysts of Nostoc | 301 |
| 11 | Acid fast bacilli | 302 |
| II C) S p otter | ||
| 12 | Antibiotic sensitivity plate set up by Kirby Bauer technique | 302 |
| 13 | Sugar fermentation tube showing acid and gas production | 303 |
| 14 | Agarose gel electrophoresis apparatus. | 303 |
| 15 | Spoiled food | 304 |
Higher Secondary – Second
Microb
Marking Scheme
Allotment of Marks
Internal Assessment
External Assesment
Total
Internal Assessment (Practicals) Marks Bre
1. Record Note Book
2. Skill of performing Experiments
Total
External Assessment Mark Break Up
1. Major Practical
2. Spotters
Total
I. Major Practical (Any one out of 5 ques
-
Aim
-
Principle
-
Procedure
-
Diagram
-
Observation
-
Results
Total
II. Spotters (Any three – one from each ca
-
Identification
-
Two salient points
-
Diagram
Total
Year Practical Examination
iology
05 marks
15 marks
20 marks
ak Up
03 marks
02 marks
05 marks
09 marks
06 marks
15 marks
tions) 9×1 = 9 marks
01 mark
02 marks
03 marks
01 marks
01 marks
01 marks
09 marks
tegory) 2×3 = 6 marks
½ marks
1 mark
½ mark
02 marks × 3 spotters = 6marks
| Microbiolog y | |
|---|---|
| Mark in g S che me | |
| Al l otme nt o f M arks | |
| Inter na l A ss es sm en t | 05 m arks |
| E xt er na l A ss esm en t | 15 m arks |
| Tot a l | 20 ma rks |
| Interna l A ss ess me nt (P r ac ti c a ls) M arks B re a k U p | |
| 1. R e co rd N ote B o ok | 03 m arks |
| 2. Sk i l l o f p er for min g E xp er im en ts | 02 m arks |
| Tot a l | 05 ma rks |
| E xt erna l A ss ess me nt M ark B re a k U p | |
| 1. Maj or P rac t ic a l | 09 m arks |
| 2. Sp otte rs | 06 m arks |
| Tot a l | 15 ma rks |
| I. Majo r P r ac ti c a l (A ny o ne o ut o f 5 q u es ti ons) 9×1 = 9 ma rks | |
| . |
- Ai m |01 m ark | .
- Pr in ci ple |02 m arks | .
- Pro c e du re |03 m arks | .
- Di ag ra m |01 m arks | .
- O bs er va t io n |01 m arks | .
- R es u lts |01 m arks | | Tot a l |09 ma rks | | II. Sp otters (A ny thr e e – o ne f rom e ach c ate go r y) 2×3 = 6 ma rks | .
- Iden t if ic at io n |½ m arks | .
- Two s a lien t p oin ts |1 m ar k | .
- Di ag ra m |½ m ar k | | Total |02 marks × 3 spotters = 6marks |
Key for Practica
I. Major Practical (Any one) 9×1 = 9 mar
1. Determine the gram nature of mi (curd/idly batter/yeast)
2. Identify whether the given fungus on its microscopic characteristics.
3. Determine the blood group of the
4. Carry out blood staining using fiel leucocytes.
5. Identify whether the given culture
II. Spotters
A. Specimen
B. Slide
C. Spotter
l Examination
ks
croorganism present in the given sample
is Aspergillus or Mucor or Rhizopus based
given blood sample.
d’s stain and observe the erythrocytes and
is catalase positive.
2 marks
2 marks
2 marks
| A. Sp e cim en | 2 m arks |
|---|---|
| B. Slide | 2 m arks |
| C. Sp otter | 2 m arks |
1. Gram’s staining of curd/idly batter/y
Aim: To determine the gram nature of micro idly batter/yeast) by Gram’s staining techniqu
Theory and Principle: Based on gram staining reaction bacteria can positive and gram negative. Gram positive ba to the gram negative bacteria. The lipid conten higher than that of gram positive bacteria. Bo take up the primary stain crystal violet and st permeability of the gram negative bacteria inc complex is given out by the gram negative ba takes up the counterstain safranin and stains r microscope after gram staining the gram po cells appear red.
Requirements: ■ Clean grease free slide ■ Nichrome loop ■ Given culture ■ Crystal violet ■ Grams iodine ■ Decolorizer(Acetone Alcohol) ■ Safranin ■ D/W
Procedure: 1. Take a loopful of the given culture and pl 2. Prepare a smear and heat fix it. 3. Cover the smear with Crystal Violet for o 4. Wash gently 5. Add Grams iodine for one minute 6. Decolorise with acetone alcohol 7. Wash the slide immediately 8. Cover the smear with safranin for a minu 9. Wash and Air dry. 10. Observe the slide under high power and o 11. Record your observations.
east
organism present in the given sample(curd/ e.
be divided into two large groups called gram cteria have thicker peptidoglycan compared t of the cell wall of gram negative bacteria is
th gram positive and gram negative bacteria ain red. When decolorized the porosity and reases due to which the crystal violet iodine cteria. Further the gram negative bacteria
ed. Hence when bacteria are observed under sitive cells appear violet and gram negative
ace on the slide.
ne minute.
te
il immersion objectives.
Diagram: (Any one Diagram)
Observation Table: ( any one shape and stai
Sr. no Morphology Arrangement C
C
1. Rod (bacilli) Singles, chains
2. Oval yeast cells Singles, budded
Results: Gram staining of the given culture shaped bacteria in chains.
2. Identification of the fungus (Asperg using LPCB.
Aim: To identify whether the given fungus is microscopic characteristics by wet mount me
Theory and Principle : Filamentous fungi are reliably identified by th such as shape, size and arrangement of spores from unicellular yeast to multicellular molds.
Common fungi are Aspergillus, Mucor collectively form mycelium. The morphology using a simple wet mount technique using lac
The organism suspended in the stain are acid preserves fungal structures and cotton bl
Fungi Characteristics of
Aspergillus sp. Septate
Mucor and Rhizopus sp. Aseptate
Gram positive bacilli
n)
olour of ytoplasm
Colour of Background Inference
Violet colourless Gram positive
Violet colourless Gram positive
revealed gram positive violet colored rod-
illus/Mucor/Rhizopus) by wet mount
Aspergillus or Mucor or Rhizopus based on thod using lactophenol cotton blue stain.
eir characteristics microscopic morphology and hyphae. Fungi are eukaryotic and range They reproduce by producing spores. and Rhizopus. They are filamentous and of the hyphae and spores can be identified tophenol cotton blue stain. killed due to the presence of phenol. Lactic ue stains the fungal cell wall.
Hyphae Spores borne in
Conidiophore bear conidia
Sporangiosphore bear sporangium containing sporangiospore.
Gram positive oval yeast
cells
| Sr. no | Mor ph ol o g y | Ar r an g em en t | C o l our o fCy top l a sm | C o l our o fBackg round | In fer en c e |
|---|---|---|---|---|---|
| 1. | R o d (b aci l li) | Sin g les, c hain s | Vio let | co lo ur les s | Gra m p osi t ive |
| 2. | O va l y e ast ce l ls | Sin g les, b udde d | Vio let | co lo ur les s | Gra m p osi t ive |
| Fu ng i | C ha r ac teris ti cs of Hy p hae | Sp ores b orne in |
|---|---|---|
| Asp e rgill us s p. | S e pt ate | C onidio phore b e ar co nidi a |
| Muco r a nd R hizo pus s p. | As e pt ate | Sporangiosphore bear sporangium containing sporangiospore. |
Requirements : ■ Clean grease free slide ■ Coverslip ■ Forcep ■ Teasing needle ■ Distilled water ■ Lactophenol Cotton Blue
Procedure: 1. Take a clean slide. 2. Place a drop of water on the slide. 3. With the help of forceps transfer the fung 4. Tease it with needle to separate the filame 5. Add a drop of lactophenolcotton blue. 6. Gently place a coverslip avoiding air bubb 7. Observe under low power and high powe 8. Read the observations and interpret.
Diagram:
al mycelium. nts (hyphae).
le formation. r objective lens.
Observation; Filamentous hyphae bearing sporangia were o
Results: Wet mount using lactophenol cotton blue w Hyphae with sporangium bearing sporangio mucor species.
3. Blood Grouping
Aim: To determine the blood group of the b
Theory and Principle: Blood grouping is an essential requirement be another.It is also useful in settling paternity d
Red blood cells contain blood group antig are present in the blood plasma.The antigens a for blood types. When RBCs of a person agglutination occurs due to antigen-antibody
Materials Required ■ Blood sample ( anticoagulated) ■ Sterile cotton ■ Sterile lancet ■ Clean dry grease free slides or white tile ■ Toothpicks ■ Marker pen ■ Commercially available Anti A sera, Anti
Procedure 1. Prick the finger under aseptic conditions 2. Place a drop of blood on the slide on each 3. Add a drop of antiserum A , B and D on A 4. Mix with toothpick using separate toothp 5. Wait for 2 mins and observe for clumpi
under microscope. 6. Interpret the results and report.
bserved.
as carried to identify the fungus sample. spores were observed. It is likely to be of
lood sample by the slide agglutination test.
fore blood is transfused from one person to isputes and medicolegal problems. ens. Antibodies to the blood group antigens re generally determined and are responsible are mixed with corresponding antiserum, reactions.
B sera and Anti D sera
side marked as A, B and D. , B and D side respectively.
icks for each mixture. ng reaction if any confirm it by observing
Interpretation If agglutination on A side the blood group is If agglutination seen on B side the blood grou If Agglutination on both A and B side the blo If No agglutination on A and B side the blood If agglutination is seen on D side the blood gr If No agglutination on D side the blood group
Diagram: ( any one depending on the result
Observation: (will vary with the type of bloo Agglutination is seen on A, B and D side
Result: The blood group of the blood sample and was found to be AB Rh positive.
34. Blood Staining
AIM To make a blood smear ,stain it using Field leucocytes.
Theory and Principle: Blood smears are used to determine leuko platelet and leukocyte morphology, and, if n counts. It is also used for diagnosis of parasite
Field’s Stain is a romanowsky stain, use and is used to stain thick and thin films. It co
A p is B od group is AB group is O oup is Rh(D) positive is Rh(D) negative.
s)
d group an example is given below)
was determined by slide agglutination test
’s stain and observe the erythrocytes and
cyte differentials, to evaluate erythrocyte, ecessary, to estimate platelet and leukocyte s like plasmodium in the blood.
d for rapid processing of blood specimens nsists of two differential stain.Field stain A
which is methylene blue and Azure dissolved component of the stain and Field stain B ma is the acidic component of the stain.These bas applied to cells.The fixator, methanol, does not basic component of peripheral white blood cell( c component that is nucleic acid of the nucleus tak The neutral components of the cells are stained b
Requirements ■ Cotton ■ Spirit ■ Blood sample ■ Clean grease free slides ■ Methanol fixative ■ Field’s stain A and Field’s stain B.
Procedure 1. Finger Prick under aseptic condition.
2. Place a small drop of blood, on one side abo
3. Without delay place another slide at an angle
4. Spread it over an area of about 2 cm2(The appears transparent.
5. After air drying the thin blood film,im minutes.
6. Flood or dip the slide in Field’s Stain A fo 7. Wash it with distilled water, 8. Flood or dip the slide in Field’s Stain B fo 9. Now air dry the smear and observe unde
Diagram
in a phosphate buffer solution.It is the basic de up of Eosin Y in a buffer solution which ic and acidic dyes induce several colours when allow any additional changes to the slide. The ytoplasm) is stained with acid dye and the acid
es on the basic dye and is stained blue to violet. y both dyes(Field’s stain A and B solution).
ut 1-2 cm from one end of a slide.
of 45° to make contact with the drop.
film should be distributed so thinly that it
merse or fix the smear in methanol for 1
r 2-3 seconds.
r 2-3 seconds and wash with distilled water. r microscope.
basophil RBC (erythrocyte)
eosinophil
lymphocyte neutrophil
Observation
TYPE OF CELL COLOUR OF CYTOPLASM
RBC pink
WBCs(leucocytes)
Neutrophil pink
Eosinophil pink
Basophil pink
lymphocyte blue
Results The blood smear was stained using field’s s observed under microscope.
5. Test for Catalase
Aim To test whether the given culture is catalase p
Theory And Principle Catalase test demonstrates the presence of ca of oxygen from hydrogen peroxide (H2O2). I produces an enzyme catalase, such as staphylo such as streptococci.
The enzyme catalase mediates the breakd water. The presence of the enzyme in a bacter is introduced into hydrogen peroxide, and the The lack of catalase is evident by a lack of or w not be more than 24 hours old.
Requirements ■ Slides ■ Nichrome loop or toothpick ■ 24hour old culture ■ 3%hydrogen peroxide ■ Dropper
COLOUR OF NUCLEUS
COLOUR OF GRANULES
- -
blue lilac
blue orange
blue Dark blue black
violet -
tain and erythrocytes and leucocytes were
ositive by the catalase test
talase, an enzyme that catalyses the release t is used to differentiate those bacteria that cocci, from non-catalase producing bacteria
own of hydrogen peroxide into oxygen and ial isolate is evident when a small inoculum rapid elaboration of oxygen bubbles occurs. eak bubble production. The culture should
| T YP E O F CELL | C OLO UR O FC Y TOP L ASM | C OLO UR O FNUCLEUS | C OLO UR O FGR ANULES |
|---|---|---|---|
| RB C | pi n k | - | - |
| WB Cs(l e u c o c y tes) | |||
| Neu t rophi l | pi n k | blu e | li l ac |
| E osin ophi l | pi n k | blu e | or ange |
| B as op h i l | pi n k | blu e | D ark b lue b l ac k |
| ly mph o c y te | blu e | v io let | - |
Procedure
Slide Method 1. Use a loop or sterile wooden stick to tran
surface of a clean, dry glass slide. 2. Place a drop of 3% H2O2 in the glass slide 3. Observe for the evolution of oxygen bubb
Diagram
Observation (any one to be reported depend
Positive: Copious bubbles produced, active b Examples: Staphylococci, E. coli, Enterobacter Negative: No or very few bubbles produced. Examples: Streptococcus and Enterococcus sp
Result The given culture was found to be catalase pos
sfer a small amount of colony growth in the
. les.
ing on the culture)
ubbling , Klebsiella, Shigella, Yersinia, Pseudomonas.
s.
itive as determined by the catalase slide test.
6. Widal Test (Slide Test)
Aim To carry out the widal test for the given bloo antibodies against salmonella antigens.
Theory And Principle Widal test is a serological test which is used f fever. Typhoid or enteric fever is caused by a (Salmonella Typhi or Salmonella Paratyphi). wall and H antigen on their flagella. On infe produce specific antibodies which are releas detect these specific antibodies in the serum using antigen-antibody interactions. These patient’s serum after 6 days of infection (fever
Salmonella Typhi possesses O antigen o Salmonella Paratyphi A and S. Paratyphi B al but have AH and BH antigen on their flagella
Widal test is an agglutination test in w detected by mixing the patient’s serum with carrying specific O, H, AH and BH antigen antibody reaction. The main principle of W present in patient’s serum, it will react with re visible clumping on the test slide.
Requirements Fresh serum The complete kit containing five vials contain ■ S. Typhi O antigen ■ S. Tyhhi H antigen ■ S. Paratyphi AH antigen ■ S. Paratyphi BH antigen
Widal positive control Widal test card or slide
v) Applicator stick
Procedure ■ Widal test can be done in two ways-one is
in which result may be obtained after one
d sample and to determine the presence of
or the diagnosis of enteric fever or typhoid gram negative bacteria Salmonella enterica Salmonella possess O antigen on their cell ction, these antigen stimulates the body to ed in the blood. The Widal test is used to sample of patients suffering from typhoid specific antibodies can be detected in the ).
n the cell wall and H antigen on flagella. so possess O antigen on their cell wall and respectively. hich specific typhoid fever antibodies are killed bacterial suspension of Salmonella s and observed for clumping ie. Antigen- idal test is that if homologous antibody is spective antigen in the suspension and gives
ing stained Salmonella antigen
rapid test on slide and another is tube test night of incubation.
Rapid slide test: 1. Clean the glass slide or test card supplied 2. Label the circles (1, 2, 3, 4, 5 and 6) in the
and Positive control 3. Place a drop of undiluted test serum in ea
O, H, AH and BH and place a drop of Neg control in circle 6.
4. Place a drop of antigen O, H, AH and BH antigen in circle 5 and O/H antigen in cir
5. Mix the content of each circle with a sep fill the whole area of the individual circle
6. Rock the test card for a minute and obser
Diagram
Observation Agglutination was observed in O and H side w of antibodies in the serum sample against Sal
Proceed for quantitative slide test or tube titre of the antibody.
Result Qualtative widal test was carried out using ra against O and H antigens of Salmonella typhi
in the kit well and make it dry. test card as O, H, AH, BH, Negative control
ch of the four labelled circle (1, 2, 3 and 4) ie ative control serum in circle 5 and Positive
in circle 1, 2, 3, and 4 respectively and no cle 6. arate wooden applicator stick and spread to . ve for agglutination.
ithin a minute which indicates the presence monella typhi antigens. test for the quantitative estimation of the
pid slide agglutination method. Antibodies were detected in the serum.
7. Demonstration of rhizobium from r
Aim: To demonstrate the presence of rhizobium in them on a nutrient medium.
Theory and Principle: Leguminous plants like cowpea, red gram , by rhizobium.Rhizobium in the soil enter in nodules and establish symbiotic association. The rhizobacteria fix nitrogen which is benef N2 fixer found to occur as bacteroids in the r be easily isolated and cultured in vitro.
Based on gram staining reaction bacteria gram positive and gram negative. Gram po compared to the gram negative bacteria. The l bacteria is higher than that of gram positiv negative bacteria take up the primary stain cr the porosity and permeability of the gram n crystal violet iodine complex is given out by th negative bacteria takes up the counterstain sa are observed under microscope after gram st and gram negative cells appear red. Rhizobia with bi-polar, sub-polar and peritrichous fl
Rhizobium grows well on Yeast Extract M to the medium differentiates rhizobia that elevated, small colonies with entire margin, Agrobacterium and other bacteria.
Requirements: 1. Root nodules (pink) of any leguminous p 2. Congo red, Yeast Extract, Mannitol Aga
oot nodules and its isolation
root nodules by gram staining and isolate
black gram contain root nodules formed to the roots of leguminous plant and form Bacteria derive nutrients from the plants. icial to the plant. Rhizobium is a symbiotic
oot nodules of leguminous plants. They can
can be divided into two large groups called sitive bacteria have thicker peptidoglycan ipid content of the cell wall of gram negative e bacteria. Both gram positive and gram
ystal violet and stain red. When decolorized egative bacteria increases due to which the e gram negative bacteria. Further the gram franin and stains red. Hence when bacteria aining the gram positive cells appear violet are Gram- negative rods which are motile agella.
annitol Agar (YEMA). Congo red added stand out as white, translucent, glistening in contrast to the red stained colonies of
lant r (pH 6.8 – 7.0):
Congo red (1% aqueous) 2.5 ml (1.0 g in 100 ml) Distilled water 1000.0 ml
3. Inoculation loop 4. Bunsen burner/laminar clean air flow hoo 5. Slides and glass rod. 6. Petri plates with YEMACR medium. 7. Sterile distilled water. 8. 95% alcohol and 0.1% HgCl2.
Procedure: 1. Wash the root system under a slow stream
the nodules are intact. 2. Select pink nodules and remove them 3. Wash and keep the nodules in 95% ethan
0.1% HgCl2. 4. Remove after five minutes and wash the n
distilled water. 5. Place the nodule on a sterile slide in a dro
with a sterile glass rod or a flat tipped for 6. Remove a loopful of this cloudy suspensi
and label. 7. Incubate in dark at 28°-30°C for 2-3 days 8. Make a smear of the remaining crushed m
negative bacilli. Even samples from the co
Diagram:
d.
of running tap water, taking care to see that
ol for a minute, wash and transfer them to
odules about four to five times with sterile
p of sterile distilled water and crush it either ceps. on and streak inoculate on YEMACR plates
and observe the colonies. aterial and gram stain and observe the gram lonies can be gram stained.
Observation Gram’s stain
Organism Morphology Arrangem
Rhizobium from root nodule.
Rod (bacilli) Singles
Colony characteristics of rhizobium on YE temperature Size – 2-4 mm Shape- circular Colour – White Margin - entire Elevation – convex, raised Opacity - semitranslucent Texture – creamy Consistency – mucilaginous Gram nature – gram negative Motility – actively motile
Results: Gram staining of the root nodule exu rods.
The colony characteristics of rhizobia wer White, creamy, mucoid colonies were obtaine
ent Colour of cytoplasm
Colour of Background Inference
red colourless Gram negative
MA after incubation for 2-3 days at room
date revealed the presence of gram negative
e studied after isolation on YEMA medium. d.
| Org anis m | Mor ph ol o g y | Ar r an g em en t | C o l our o fc y to p l a sm | C o l our o fBackg round | In fer en c e |
|---|---|---|---|---|---|
| R hizo bium f romro ot n o du le . | R o d (b aci l li) | Sin g les | re d | co lo ur les s | Gr am nega t ive |
Spotters
II A) Specimen
1. Root nodules of leguminous plant
■ Leguminous plants like cowpea, red gram ■ Rhizobium in the soil enter into the roots
establish symbiotic association. ■ Bacteria derive nutrients from the plants. ■ The rhizobacteria fix nitrogen which is be
2. Tikka leaf spot of groundnut plant
contain root nodules formed by rhizobium. of leguminous plant and form nodules and
neficial to the plant.
■ Tikka leaf spot disease is a kind of fungal ■ This disease is caused by Cercaspora perso ■ Brown spots surrounded by a yellow halo ■ The fungal spores can be demonstrated i
microscope.
3. Mushroom
■ Mushroom is a saprophytic fungus. ■ Primary mycelium grows from basidiospo ■ It has high protein content and edible mus ■ Example: Agaricus species and Pleurotus s
4. Sand fly
disease seen in groundnut leaf. nata.
appear on the upper surface of the leaf. f the leaf is processed and observed under
res. hrooms are used as food. pecies.
■ Bite of an infected sandfly transmits leishm ■ Female sandfly during a blood meal inges
the blood. ■ In the midgut these are transformed to fla
5. Ascaris
■ The adult worm of ascaris lives in the sma ■ They are large cylindrical worms with tap
than the posterior end ■ The adult male worm is smaller than fema
IIB) Slide
6. Cyst of Entamoeba histolytica
■ Cyst is one of the three forms of entamoeb ■ A mature cyst is a quadrinucleate spherica ■ Mature cysts are passed in the stool of infe ■ Direct examination of wet mount of stool f
ania donovani infection. t free as well as intracellular amastigotes in
gellated promastigote.
ll intestine of humans ering ends, the anterior end being thinner
le worms.
a histolytica l body. cted person
or cysts is diagnostic of intestinal amoebiasis
7. Penicillium species
■ Colony of penicillium are initially white an and turn into shades of green or blue gree
■ Hyphae are hyaline and septate ■ Condiophores are long, give rise to branch ■ Phialids branch and give the appearance o ■ They produce sterigmata bearing chain of
and measure 1-2micrometer.
8. Microfilariae ■ Filariasis is caused by nematodes (roundw
the lymphatics and subcutaneous tissues. ■ The female worms release the first stage la
in the peripheral blood. ■ Identification of microfilariae by micro
diagnostic procedure. ■ The blood sample can be a thick smear, st ■ The larva measures about 290microns in l
d fluffy and later produce pigmented spores n
ing phialids f brush or penicillins conidia (spores) which are oval or spherical
orms) like Wuchereria bancrofti that inhabit
rvae called microfilariae, which are detected
scopic examination is the most practical
ained with Giemsa. ength and 6-7micron in breath.
9. Egg of Ascaris lumbricoides
■ These are passed in stool of the infected h ■ Brownish due to bile pigment. ■ Fertilised eggs are rounded and have a thi ■ Unfertilised eggs are elongated and larger ■ When ingested through water or contamin ■ Microscopic identification of eggs in th
diagnosing intestinal ascariasis.
10. Heterocysts of Nostoc
■ Heterocysts are specialized structures havin blue green algae like Nostoc, Anabena.
■ They may be terminal or found in between of pores.
■ They are sites of atmospheric nitrogen fix ■ They serve as a store house of food materi
ost.
ck shell (chitinous). than fertile eggs. ated food by human it causes Ascariasis. e stool is the most common method for
g thick cell wall formed in some filamentous
the vegetative cells attached to it by means
ation. al.
11. Acid fast bacilli
■ Acid fast bacilli contains mycolic acid in th however once stained cannot be decolouri
■ Special method like Ziehl- Neelson’s Carb ■ The acid- fast bacilli are stained red in col
when counterstained with methylene blue ■ Mycobacterium tuberculosis is and acid fa
IIC) Spotter
12. Antibiotic sensitivity plate set up by Kir ■ Kirby Bauer technique is used to determ
various antimicrobial agents. ■ Standard suspensions of rapidly growing t
muller hinton agar plates. ■ Antibiotic discs are pressed on the surface ■ The zone of inhibition or the zone of grow
the organism towards antibiotic.
eir cell walls hence do not get stained easily, sed easily. ol fuchsin is used to stain acid fast bacilli. our while the non acid fast cells appear blue . st bacilli.
by Bauer technique ine the susceptibility of the organism to
est bacterium is inoculated on the surface of
of the seeded plates. th determines the degree of susceptibility of
13. Sugar fermentation tube showing acid a ■ Carbohydrate broth with bromocresol pur
of pure bacterial culture to ferment a spec other sugars.
■ Acid production is indicated by colour ch ■ Gas production is indicated by an air bubb ■ Escherichia coli ferments lactose producin
14. Agarose gel electrophoresis apparatus. ■ Electrophoresis refers to the movement of ■ The negatively charged molecules move
positively charged molecules migrate towa ■ Gel electrophoresis is a routinely used a
purification of specific DNA fragments. ■ As the DNA is negatively charged, DNA f
positive electrode. The rate of migration o
nd gas production ple as indicator is used for testing the ability ific sugar like lactose, xylose, mannitol and
ange of the indicator from purple to yellow le in the durham’s tube. g acid and gas.
charged molecules in an electric field. towards the positive electrode while the rds the negative electrode. nalytical technique for the separation and
ragments move through the gel towards the f DNA is dependent on the size and shape.
15. Spoiled food ■ Spoilage is a process in which food dete
reduced. ■ Food poisoning may result on eating cont ■ Foods spoil due to attacks from enzymes, ■ These include bacteria, mold, yeast, moist
riorates such that its quality of edibility is
aminated or spoiled food. oxidation and microorganisms. ure, temperature and chemical reaction.