CBSE Class 12 Question Paper 2026 Solution Medical Diagnostics

FOR CBSE CLASS 12 EXAM PREPARATION

CBSE Class 12 2026
Question Paper
Solution · Medical
Diagnostics
EXAM YEAR TYPE SUBJECT

CBSE Class 12 2026 Question Paper Solution Medical Diagnostics

Notes · Sample Papers · Previous Year Papers · Mock Tests

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Strictly Confidential a
Marking Scheme

(For Internal and Restricted use only)
Senior Secondary School Examination, 2026 (XIIth)
SUBJECT NAME : Medical Diagnostics (Q.P. CODE 828/352)

General Instructions: -
1 The CBSE has decided to introduce On Screen Marking (OSM) for the evaluation of
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Class XII answer Book with the 2026 Examination.
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2 You are aware that evaluation is the most important process in the actual and correct

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assessment of the candidates. A small mistake in evaluation may lead to serious

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problems which may affect the future of the candidates, education system and
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teaching profession. To avoid mistakes, it is requested that before starting evaluation,
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a“Evaluation
you must read and understand the spot evaluation guidelines carefully.
3 policy is a confidential policy as it is related to the confidentiality
of the examinations conducted, evaluation done and several other aspects. Its
leakage to public in any manner could lead to derailment of the examination
system and affect the life and future of millions of candidates. Sharing this
policy/document to anyone, publishing in any magazine and printing in
Newspaper/Website, etc. may invite action under various rules of the Board
and IPC.”
4 Evaluation is to be done as per instructions provided in the Marking Scheme. It should

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not be done according to one’s own interpretation or any other consideration. Marking

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Scheme should be strictly adhered to and religiously followed. However, while

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evaluating, answers which are based on latest information or knowledge and/or

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are innovative, they may be assessed for their correctness otherwise and due

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marks be awarded to them. In Class-XII, while evaluating two competency-
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based questions, please try to understand given answer and even if reply is not
from marking scheme but correct competency is enumerated by the candidate,
due marks should be awarded.
5 The Marking scheme carries only suggested value points for the answers.
These are in the nature of Guidelines only and do not constitute the complete answer.
The students can have their own expression and if the expression is correct, the due
marks should be awarded accordingly.
6 The Head-Examiner must go through the first five answer books evaluated by each
evaluator on the first day, to ensure that evaluation has been carried out as per the
instructions given in the Marking Scheme. If there is any variation, the same should
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be zero after deliberation and discussion. The remaining answer books meant for

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evaluation shall be given only after ensuring that there is no significant variation in

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the marking of individual evaluators.
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Evaluators will mark ( √ ) wherever answer is correct. For wrong answer CROSS ‘X’
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be marked. Evaluators will not put right (✓) while evaluating which gives an

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impression that answer is correct and no marks are awarded. This is most common
mistake which evaluators are committing.
8 If a question has parts, please award marks on the right-hand side for each part in
the OSM Portal. Marks awarded for different parts of the question will be totaled up
by the OSM System.
9 If a question does not have any parts, marks must be awarded in the left-hand margin
in the OSM Portal. This may also be followed strictly.

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10 No marks to be deducted for the cumulative effect of an error. It should be penalized
only once.
11 A full scale of marks __________ (example 0 to 80/70/60/50/40/30 marks as given in
Question Paper) has to be used. Please do not hesitate to award full marks if the
answer deserves it.
12 Every examiner has to necessarily do evaluation work for full working hours i.e., 8
hours every day and evaluate 20 answer books per day in main subjects and 25
answer books per day in other subjects (Details are given in Spot Guidelines).This is
in view of the reduced syllabus and number of questions in question paper.
13 Ensure that you do not make the following common types of errors committed by the
Examiner in the past :-
● Answers marked as correct, but marks not awarded. (Ensure that the right tick
mark is correctly and clearly indicated. It should merely be a line. Same is with
the X for incorrect answer.)
● Half or a part of answer marked correct and the rest as wrong, but no marks
awarded.
14 While evaluating the answer books if the answer is found to be totally incorrect, it
should be marked as cross (X) and awarded zero (0) Marks.
15 The Examiners should acquaint themselves with the guidelines given in the
“Guidelines for Spot Evaluation” before starting the actual evaluation.
16 The candidates are entitled to obtain photocopy of the Answer Book on request on
payment of the prescribed processing fee. All Examiners/Additional Head
Examiners/Head Examiners are once again reminded that they must ensure that
evaluation is carried out strictly as per value points for each answer as given in the
Marking Scheme.
17 If a candidate attempts both alternatives/options in a question where only one
option/ alternative is required to be attempted, the Evaluator shall award marks
in both the options. The system will take the higher of two scores and
disregard the other response.
18 In a question having two options/alternatives, if a candidate has attempted only
one, then the evaluator shall mark “NA” (Not attempted) against the option that
has not been attempted by the candidate.

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MARKING SCHEME
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Medical Diagnostics (Subject Code- 828)
(PAPER CODE: 352) (P3520828)
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Q.No. Question Source Material UNIT/Chapter Mar
(NCERT/PSSCI No. ks
VE/CBSE Study
Material)
SECTION – A
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(Objective Type Question)
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1. Answer any 4 out of the given 6 questions on

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Employability Skills (414 marks)
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(i)
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(A) listening 1

(ii) (C) deadlines U-2 Pg-30 1

(iii) FFM stands for Five Factor Model of individual’s U-2 Pg-33 1
personality
(iv) (D) cell U-3 Pg-41 1

(v) overselves, abilities U-4 Pg-93 1
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(vi) Roof top rainwater harvesting refers to the process U-5 Pg-116 1

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where rainwater is collected in tanks to be used later.
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2.
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Answer any 6 out of the given 7 questions (616
marks)
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(i) (A) Field’s stain CBSE Study Hematology 1
Material Lab; 3.5
Reagents-
Preparation and
their uses
(ii) (B) hemoglobinometer CBSE Study Blood Bank and 1
Material Transfusion;
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Material and
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Equipment
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. (A) interpretation of exfoliative cells s
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1

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Cytopathology
(iv) (B) Centrifuge CBSE Study Hematology 1
Material Lab; 3.2
Hematology Lab
Instruments
(v) (B) squamo – columnr junction CBSE Study Cytopathology, 1
Material Female Genital
tract
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(vi) (B) 4 CBSE Study Blood Bank and 1
Material Transfusion;
Laws of Blood
Smear
(vii) (A) homogeneous spread CBSE Study Hematology 1
Material Lab; 3.4
Preparation of
Blood Smear
3. Answer any 6 out of the given 7 questions (616
marks)
(i) (C) Le a and Le b CBSE Study Blood Bank and 1
Material Transfusion;
Practical
Importance of
Other Blood
Groups
(ii) (B) Pap smear test CBSE Study Cytopathology, 1
Material Female Genital
tract
(iii) (A) Thromboplastin CBSE Study Hematology 1
Material Lab; 3.3
Collection of
Blood samples
(iv) (D) lg G CBSE Study Blood Bank and 1
Material Transfusion; Rh
Antibody titers
(v) (C) Respiratory tract malignancies CBSE Study Cytopathology, 1
Material Respiratory
Tract
(vi) (B) Basophilic CBSE Study Hematology 1
Material Lab; 3.6
Staining
Methods
(vii) (D) May-Grunwald-Giemsa (MGG) CBSE Study Cytopathology, 1
Material FNAC
4. Answer any 5 out of the given 6 questions (515
marks)
(i) (A) transparent plexiglass CBSE Study Blood Bank and 1
Material Transfusion;
Equipment used
for storage of
blood
(ii) (B) Ether alcohol mixture CBSE Study Cytopathology, 1
Material Cytopathological
Fixatives

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se (iii) (D) Thrombocytosis
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CBSE Study
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Hematology 1

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Material Lab; 3.7
measurements
or Quantitative
Analysis
(iv) (A) Proteins CBSE Study Blood Bank and 1
Material Transfusion;
Basis of
Immunology

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(v) (C) Giemsa and Distilled water CBSE Study Cytopathology; 1

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Material 6.6 Staining
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produce in

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Cytology
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(D) Complete CBSE Study
Material
Hematology
Lab; 3.1
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5. Answer any 5 out of the given 6 questions (515
marks)
(i) (C) i and iii CBSE Study Cytopathology, 1
Material Safety in the
Laboratory
(ii) (D) Hematopoietic CBSE Study Hematology 1
Material Lab; 3.8
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Anaemia
(A) ABO antigens and antibodies Blood Bank and 1
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(iii)

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ABO Blood

(C) Xylene ag CBSE Study
Group System
Cytopathology 1
(iv)
Material
(v) (A) Wintrobe’s CBSE Study Hematology 1
Material Lab; 3.7
Measurements
or Quantitative
Analysis

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(vi) (A) O or B CBSE Study Blood Bank and 1

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Material
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Transfusion;

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group system

s Answer any 5 out of the given 6 questions (515
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a (i) (C) Transfusion adverse reaction reports CBSE Study
Material
Blood Bank and
Transfusion;
1

Records in
Blood Bank
(ii) (C) Erythropoietin CBSE Study Hematology 1
Material Lab; 3.8
Anaemia

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(iii) (A) Fixation CBSE Study Cytopathology 1
Material 6.4 Cytological
fixation
(iv) (A) Clotting time CBSE Study Hematology 1
Material Lab; 3.9
Hemostasis
(v) (A) Fine needle aspiration cytology CBSE Study Cytopathology; 1
Material 6.3 FNAC
(vi) (A) Landsteiner CBSE Study Blood Bank and 1
Material Transfusion;
ABO Blood
Group System
SECTION – B
(Subjective Type Question)
Answer any 3 out of the given 5 questions on
Employability skills (3x2=6 marks) Answer each
question in 20 – 30 words.
7. Four barriers are: - U-1 Pg-6 2
Physical barrier
Psychological barrier
Linguistic and Cultural barrier 0.5x
Personal factors 4
Noise and Visual distractions
8. (i) Personality development is the development of U-2 Pg-33 2
an organised pattern of behaviours and (1x
attitudes that makes a person distinctive. 2)
(ii) It occurs by the ongoing interaction of
temperament, character and environment.

9. Electronic spreadsheets have many options to make U-3 Pg-54 2
the content look neat and easy to read. This is called (1+
formatting. 1)
Eg.
(i) Aligning the text
(ii) Highlighting the text
10. (i) They provide their expertise in services to U-4 Pg-83 2
create a market for technical entrepreneurs. (1x
(ii) They are not concerned with the 2)
manufacturing process but have more to do
with before and after the manufacturing
process.
11.Green workers services include: - U-5 Pg-112 2
(i) Electricians – Who install solar panels (½x
(ii) Plumbers – Who install solar water heaters 4)
(iii) Construction workers – Who build energy-
efficient green buildings
(iv) Technicians and workers – Involved in
establishing wind power farms and those
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working for clean and renewable energy
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development.
Answer any 3 out of the given 5 questions (326
marks) answer each questions in 20-30 words.

12. Factors Influencing Sedimentation: CBSE Study Hematology 0.5 x
Material Lab; 3.7.8 4= 2
(1) Fibrinogen, Globulin, Cholesterol: These
factors increase the sedimentation rate. Erythrocyte
Sedimentation
RBC count – The higher the RBC count lower
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(2) Rate

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the ESR.
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(3)
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Sex: It is generally greater in women.
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(4)
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Pregnancy – An increased ESR is seen from
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the 3rd month of pregnancy and returns to
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normal 4 weeks after delivery.

13. It is used for the actual collection of blood. It can CBSE Study Blood Bank and 2
collect the desired volume of blood from the donor Material Transfusion,
which is either 350 or 450 ml. It has a visible volume Equipment for
display and flow rate also. There is a audible alarm blood collection
if the flow of blood is slow. There is a provision for
automatic clamping when the volume is reached.
After collection this once again gives an audible
alarm.
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. the CBSE Study
14. (1) Adequate sample is ensured (vacuum in
tube controls the amount of blood s
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Hematology 0.5 x

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entering Lab; 3.3 4= 2
tube).
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(2) Correct ratio of anticoagulant
Collection of
blood samples
ensured.
(3) This is a closed system and spillage of blood
and hence any Biohazard is thus avoided.
(4) Large amounts of blood (in multiple tubes) can
be collected with minimum discomfort to the
patient.
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15.
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Endo-cervical brush is a small bottlebrush-like CBSE Study
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Cytopathology;
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m . device with one end having fine bristles made up of Material
s e Female Genital

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nylon. This device is strictly for taking materials
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from the endocervix. Gently insert the brush in the

g endocervix and rotate one turn, pressing against the a
a upper and lower walls. The cytobrush is similar to
that of an endocervical brush except that the
projected tip is without bristles. This can be used
for obtaining cells from the whole cervix.

16. Platelet incubator –22 C specifically designed to CBSE Study Blood Bank and 1+1
maintain donor platelets in an even suspension Material Transfusion, =2
throughout the blood plasma. Equipment used

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of blood

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Platelet Agitator- It agitates at the fixed speed of 70
to 80 strokes per minute.
Answer any 2 out of the given 3 questions (236
marks). Answer each question in 30-50 words.
17. Nuclei: Blue/Black CBSE Study Cytopathology; 3
Cytoplasm: Pink/Blue Green Material 6.6 Staining
Non-keratinising squamous cells: Blue/Green Procedures In
Keratinizing cells: Pink/Orange Cytology
18. Landsteiner discovered the ABO group antigens CBSE Study Blood Bank and 3
in1900 and since then this is one of the most Material Transfusion;
important discoveries in the field of medicine. The ABO Blood
reciprocal relation between ABO antigens and group system
antibodies is called Landsteiner’s law.
Cell grouping serum grouping blood
group
anti- anti- anti- A cells B cells
A B AB
     A
     B
     O
     AB
19. Some of the problems encountered during CBSE Study Hematology 1+1
staining: Material Lab; 3.6 +1=
Excessive blue stain is seen with thick film, Staining 3
prolonged staining, inadequate washing and too high Methods
an alkalinity of stain or diluent. Remedial actions are
using less stain or more diluents, staining for a
shorter time and changing to a buffer with a low pH
Excessive pink stain is seen with Insufficient
staining, Prolonged washing, Mounting the
coverslips before drying, too high an acidity of stain
or buffer or methyl alcohol and the dye with
improper polychromes (Try another lot)
Precipitate on the film occurs with Dirty slides,
Drying of film during the staining procedure,
Improper washing of the slides, Improper Filtration
of the stain and the presence of dust on the slide or
smear.
Answer any 3 out of the given 5 questions (3412
marks). Answer each question in 50-80 words.

20. Coagulation system serves to convert plasma
fibrinogen into solid mass of fibrin. The CBSE Study Hematology 1+1
coagulation system is involved in haemostatic Material Lab; 3.9 +1+
process as well as in thrombus formation. Hemostasis 1=4
Intrinsic pathway: Contact with abnormal surface
leads to activation of factor XII and the sequential
interactions of factors XI, IX, VIII and finally factor
X, along with calcium ions (factor IV) and platelet
factor 3.

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se Extrinsic pathway: Damage to tissue results in the
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release of tissue factor or thromboplastin. The
tissue factor’s interaction with factor VII activates
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factor X.

Common pathway: It begins where both intrinsic
and extrinsic pathways converge to activate factor
X which forms a complex with factor Va and
platelet factor 3, in the presence of calcium ions.

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This complex activates prothrombin to thrombin

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which then converts fibrinogen to fibrin. The
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monomeric fibrin so formed is polymerized to

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insoluble fibrin by activation of factor XIII.

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The antigen – antibody reactions ingvitro
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21.
CBSE Study Blood Bank and 1+1
Material Transfusion, +1+
(1) Agglutination is defined as the clumping of The antigen- 1=4
particles that have an antigen on their surface antibody
and is brought about by antibodies. This forms reactions in vitro
the basis of blood grouping tests.

(2) Hemolysis: Rupture of red cells with release of
intracellular haemoglobin can occur if the
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Antibody has the property of hemolysin. It
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c. o (3) Precipitation is the formation of a visible
requires the presence of a complement.
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(4) Enzyme-linked immunosorbent assay
(ELISA): Here, an enzyme label is used and a
colour reaction that takes place in the presence
of a substrate denotes the presence of an
antigen/antibody as the case may be. This is
the principle used in Transfusion Transmitted
Disease tests.

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22. Rountine Fixatives : Freshly prepared smears can be CBSE Study Cytopathology; 1+1
immediately submerged in a liquid fixative. This is Material Cytological +1+
called wet fixation and is the ideal method for fixing Fixatives 1=4
all gynecological and non-gynecological smears.
Any of the following alcohols can be used:
(Explain Any 3).
(1) 95% Ethyl Alcohol (Ethanol): The ideal
fixative recommended in most of the
laboratories for cytological specimens is 95%
ethanol alone. It produces optimal nuclear
details but some amount of cell shrinkage.
Absolute (100%) ethanol produces a similar
effect on cells. But is much more expensive.
(2) Ether alcohol mixture: This fixative was
originally recommended by Papanicolaou. It
consists of equal parts of ether and 95% ethyl
alcohol. It is an excellent fixative, but ether is
not used in most of the laboratories because of
its safety hazards, odour and hygroscopic
nature.
(3) 100% Methanol: 100% methanol is an
acceptable substitute for 95% ethanol.
Methanol produces less shrinkage than
ethanol, but it is more expensive than ethanol.
(4) 80% propanol and isopropanol: They cause
slightly more cell shrinkage than ether ethanol
or methanol. By using lower percentage of
these alcohols, the shrinkage is balanced by the
swelling effect of water on cells.
(5) Denatured alcohol: It is ethanol that has been
changed by the addition of additives in order to
render it unsuitable for human consumption. It
can be used at a concentration of 95% or 100%.
23. The magnification system is the optical component
of the microscope. That magnifies the object placed CBSE Study Blood Bank and 4
on the stage. It is done by the combination of two Material Transfusion;
series of lenses. The objective and the eyepiece. The Equipment and
objective stays near the object of the tube. The low- regents for
power objective (10x) is the smallest in size, usually testing of blood
with a green ring on the objective for easy
identification and when the image is in focus, the
low-power objective has the largest working distance
(5 to 6mm).
The working distance is the distance between the
front lens and the objective side. The working
distance decreases with increasing magnification and
is 0.5 to 1.5mm in the case of the high power and
0.15 to 0.20mm in the case of the oil-immersion
objective. The eyepiece magnifier is put on a screen.
The total magnification of the object is the product
of the magnifying powers of the objective and the

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eyepiece. Thus, with 10x magnification of the
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eyepiece, the low power objective gives 10x10100x
total magnification. The high power 10x40400x
magnification and for the oil-immersion lens,
10x1001000x magnification. The cost of the lens
increases with higher magnification. When using oil
immersion, a drop of cedar wood oil is applied
directly on the smear.
24. General guidelines for storage and archival in a CBSE Study Storage and 1+1
pathology laboratory: (Any 4) Material Archiving of +1+
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(1) Report duplicates / records / diagrams and Specimens 1=4

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Copies of any representative images prepaid
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should be kept for atleast 20 years.

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(2) All laboratories
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minimum of five years.
(3) As some patients with cancer service for more
than 10 years, therefore it is recommended that
once the regulated length of time for storage is
met, institutions may continue to store
cytology slides based on the room they have
for storage.
(4) The entire archive should be professionally
stored in a climate-controlled environment and
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its index should be available, preferable in
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digital format.
(5)
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Paper records should be stored as bounded

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volumes. All documents, relevant radiographs
and additional material available should be
photographed and scanned to be digitally
archived as well.

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