Laboratory0112

13/11/2025

11/10/2025

11/10/2025

Coombs Test (Direct and Indirect)
1. Objective:
The objective of the Coombs test was to detect antibodies that act against red blood cells (RBCs).
• The Direct Coombs Test (DCT) was used to detect antibodies or complement proteins attached directly to RBCs in the body.
• The Indirect Coombs Test (ICT) was used to detect antibodies present in the serum that could bind to RBCs.
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2. Principle:
The test was based on antiglobulin reaction. The Coombs reagent (anti-human globulin) reacted with human antibodies or complement proteins bound to RBCs, causing agglutination (clumping).
• Direct Test: Detected antibodies already attached to patient RBCs.
• Indirect Test: Detected free antibodies present in the serum that could bind to RBCs.
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3. Materials:
• Patient’s blood sample (EDTA tube for DCT, plain tube for ICT)
• Washed red blood cells (RBC suspension)
• Coombs (Anti-human globulin) reagent
• Centrifuge
• Test tubes
• Normal saline
• Pipettes
• Water bath (optional for warming)
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4. Procedure:
A. Direct Coombs Test (DCT):
1. The patient’s RBCs were washed three times with normal saline.
2. One drop of washed RBCs was placed in a clean test tube.
3. One drop of Coombs reagent was added.
4. The mixture was gently mixed and centrifuged for 1 minute.
5. The tube was observed for agglutination.
B. Indirect Coombs Test (ICT):
1. Patient’s serum was incubated with test RBCs (having known antigens) at 37°C for 30 minutes.
2. The cells were then washed three times with normal saline to remove unbound antibodies.
3. One drop of Coombs reagent was added.
4. After mixing and centrifuging, the tube was observed for agglutination.
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5. Result:
• Positive: Agglutination seen → presence of antibodies.
• Negative: No agglutination → absence of antibodies.
Test Type Positive Result Indicates
Direct Coombs Autoimmune hemolytic anemia, hemolytic disease of newborn (HDN), drug-induced hemolysis
Indirect Coombs Alloantibodies in serum, used for blood compatibility testing and prenatal screening
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6. Uses:
• To diagnose autoimmune hemolytic anemia.
• To detect HDN (Hemolytic Disease of the Newborn).
• To perform cross-matching before blood transfusion.
• To detect antibody sensitization in pregnancy or transfusion reactions.
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7. Consultation:
If the Coombs test was positive, the patient was advised to consult a hematologist for further investigation and management. In pregnancy, a positive indirect Coombs test required close monitoring to prevent HDN in the baby.

27/09/2025

Coombs Test (Direct and Indirect Antiglobulin Test)
1. Objective:
The objective of the Coombs test was to detect the presence of antibodies or complement proteins bound to the surface of red blood cells (RBCs). The Direct Coombs Test (DAT) aimed to identify antibodies attached directly to the patient's RBCs, while the Indirect Coombs Test (IAT) was performed to detect free antibodies present in the patient's serum that could react with RBC antigens.

2. Principle:
The principle of the Coombs test was based on the detection of antigen–antibody reactions. In the Direct Coombs Test, RBCs coated with immunoglobulin (IgG) or complement were mixed with Coombs reagent (anti-human globulin). The reagent cross-linked the sensitized RBCs, causing visible agglutination.
In the Indirect Coombs Test, the patient's serum containing antibodies was first incubated with donor or test RBCs. If the antibodies in the serum bound to the antigens on the RBCs, the subsequent addition of Coombs reagent caused agglutination. The appearance of agglutination indicated a positive test result.

3. Materials:
• Patient's blood sample (for Direct Coombs Test)
• Patient's serum (for Indirect Coombs Test)
• Test RBCs (antigen-positive cells for IAT)
• Coombs reagent (anti-human globulin serum)
• Test tubes
• Pipettes
• Centrifuge
• Microscope
• Isotonic saline solution
• Glass slides

4. Procedure (Microscopic):
a) Direct Coombs Test (DAT):
1. A blood sample was collected from the patient, and RBCs were washed three times with isotonic saline to remove unbound antibodies.
2. The washed RBC pellet was suspended in saline to make a 2–5% RBC suspension.
3. Two drops of Coombs reagent were added to the washed RBC suspension in a test tube.
4. The tube was mixed gently and centrifuged for 1–2 minutes at 1000 rpm.
5. The sediment was examined microscopically for agglutination.
6. The presence of clumping indicated a positive Direct Coombs Test.
b) Indirect Coombs Test (IAT):
1. Two drops of the patient’s serum were mixed with one drop of test RBC suspension in a test tube.
2. The mixture was incubated at 37°C for 30 minutes to allow antibodies to bind to RBC antigens.
3. After incubation, the RBCs were washed three times with saline to remove unbound antibodies.
4. Two drops of Coombs reagent were added to the washed RBCs.
5. The tube was centrifuged for 1–2 minutes and then examined microscopically.
6. Agglutination of RBCs indicated a positive Indirect Coombs Test.

5. Result:
• Positive Result: Visible clumping or agglutination of RBCs was observed under the microscope, indicating the presence of antibodies bound to RBCs (DAT) or free antibodies in the serum (IAT).
• Negative Result: No agglutination was observed, indicating the absence of significant antibodies.

6. Uses:
• To diagnose autoimmune hemolytic anemia by detecting autoantibodies attached to the patient's RBCs.
• To screen for hemolytic disease of the newborn (HDN) caused by Rh incompatibility between mother and fetus.
• To cross-match blood during transfusion to prevent hemolytic transfusion reactions.
• To detect antibodies in patients receiving multiple transfusions.
• To monitor patients for immune-mediated drug reactions affecting RBCs.

7. Consultation:
If the test result was positive, the patient was advised to consult a hematologist or immunologist for further evaluation and management. In cases of suspected hemolytic disease of the newborn, immediate neonatal care was recommended. For blood transfusion-related incompatibilities, the blood bank physician was consulted to ensure safe transfusion practices. The patient was counseled about possible causes and preventive measures, including Rh immunoglobulin administration in Rh-negative mothers.

20/09/2025

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20/09/2025

A some MCQs about laboratory

11/09/2025

09/09/2025

1. Which of the following is a common anticoagulant used in blood collection?
A) EDTA
B) NaCl
C) Glucose
D) Albumin

2. The normal pH of human blood is approximately:
A) 6.8
B) 7.4
C) 8.2
D) 7.0

3. Which test is used to detect diabetes?
A) CBC
B) Blood Glucose Test
C) Urine Culture
D) LFT

4. In microbiology, Gram staining differentiates bacteria based on:
A) Shape
B) Cell Wall Composition
C) Motility
D) Oxygen Requirement

5. Which vitamin is essential for blood clotting?
A) Vitamin A
B) Vitamin D
C) Vitamin K
D) Vitamin C

6. What does CBC stand for?
A) Complete Blood Count
B) Calcium Blood Check
C) Cell Biology Culture
D) Complete Biochemistry

7. Which organ produces insulin?
A) Liver
B) Pancreas
C) Kidney
D) Heart

8. The term “aseptic technique” is used in:
A) Sterilization
B) Blood Pressure Measurement
C) X-ray Imaging
D) Centrifugation

9. Hemoglobin is mainly found in:
A) Plasma
B) RBCs
C) WBCs
D) Platelets

10. Which electrolyte is most abundant in extracellular fluid?
A) Potassium
B) Sodium
C) Calcium
D) Magnesium

11. PCR (Polymerase Chain Reaction) is used for:
A) Blood Typing
B) DNA Amplification
C) Urine Analysis
D) Antibody Detection

12. Which of the following is NOT a type of WBC?
A) Neutrophil
B) Eosinophil
C) Thrombocyte
D) Basophil

13. Which stain is used for identifying Mycobacterium tuberculosis?
A) Gram Stain
B) Ziehl-Neelsen Stain
C) Crystal Violet
D) Methylene Blue

14. Normal body temperature in Celsius is:
A) 35°C
B) 36.5–37.5°C
C) 38–39°C
D) 34–35°C

15. Which test is commonly used for liver function?
A) LFT
B) RFT
C) CBC
D) ECG

16. Urine is normally:
A) Sterile
B) Full of Bacteria
C) Acidic
D) Basic

17. What is the main function of platelets?
A) Oxygen Transport
B) Blood Clotting
C) Immune Defense
D) Hormone Transport

18. Which gas is essential for human respiration?
A) Nitrogen
B) Carbon Dioxide
C) Oxygen
D) Hydrogen

19. Which part of the microscope controls light intensity?
A) Objective Lens
B) Eyepiece
C) Diaphragm
D) Stage

20. Blood collected in a plain tube (no anticoagulant) will:
A) Remain Liquid
B) Form Clot
C) Turn Red
D) Separate Plasma Only

28/07/2025

Fertility Test (Microscopic Examination of Semen)

1. Objective:

The objective of the fertility test was to assess male fertility by examining semen for s***m count, motility, morphology, and other parameters under a microscope.

2. Principle:

The principle of the test was based on microscopic analysis of semen to evaluate the quality and quantity of s***matozoa. This helped determine the potential fertility of a male.

3. Materials:

Clean, sterile semen collection container

Glass slides and coverslips

Micropipette or dropper

Light microscope (with 40x magnification)

Timer or stopwatch

Staining reagents (e.g., Eosin-Nigrosin for morphology)

Incubator (37°C)

Personal protective equipment (PPE)

4. Procedure (Microscopic):

1. The semen sample was collected after 2–7 days of abstinence in a sterile container.

2. It was allowed to liquefy at room temperature for 30 minutes.

3. A drop of semen was placed on a glass slide and covered with a coverslip.

4. Under the microscope, s***m motility was first observed at 40x magnification.

5. Another slide was prepared and stained for assessing morphology and counted under oil immersion (100x).

6. S***m concentration was calculated using a Neubauer counting chamber if needed.

7. Volume, viscosity, and appearance were also noted.

5. Result:

A normal semen sample showed >15 million s***m/mL, with at least 40% motile and >4% normal morphology.

Abnormal results included low s***m count (oligos***mia), poor motility (asthenozoos***mia), or no s***m (azoos***mia).

6. Uses:

It was used to assess male fertility in couples facing infertility issues.

It helped diagnose reproductive tract infections, hormonal imbalances, or genetic disorders affecting s***m production.

7. Consultation:

Based on the results, patients were advised to consult a fertility specialist or urologist. Further hormonal tests, imaging, or genetic counseling were recommended if abnormalities were detected.................
Female Fertility Test

1. Objective:

The objective of the female fertility test was to assess the reproductive health of a woman by evaluating ovulation, cervical mucus, and hormonal levels.

2. Principle:

The principle was based on detecting signs of ovulation and the body's readiness for conception. Microscopic analysis of cervical mucus and hormone testing (like LH, FSH, and estrogen) provided insights into the woman’s fertility status.

3. Materials:

Sterile swab or speculum

Glass slides and coverslips

Microscope

Staining solution (optional)

Hormonal assay kits (for LH, FSH, prolactin, estrogen)

Basal body temperature (BBT) chart

Ovulation prediction kit (optional)

4. Procedure (Microscopic):

1. A cervical mucus sample was collected around the mid-cycle (Day 12–16).

2. A drop of mucus was placed on a slide and covered with a coverslip.

3. The sample was observed under a microscope for fern-like crystallization, indicating the presence of estrogen and ovulation.

4. Hormonal tests were performed using blood samples to check levels of LH, FSH, estradiol, and progesterone.

5. Basal body temperature charts were reviewed to confirm ovulatory patterns.

5. Result:

Normal results showed fern pattern in cervical mucus and hormone levels within normal ovulatory ranges.

Abnormal findings included absence of ferning, low progesterone (indicating anovulation), or high FSH (suggesting poor ovarian reserve).

6. Uses:

It was used to identify causes of female infertility.

Helped determine ovulation status and hormonal imbalances.

Guided treatment in cases like polycystic ovarian syndrome (PCOS), thyroid issues, or early menopause.

7. Consultation:

Based on the results, women were referred to a gynecologist or reproductive endocrinologist. Additional imaging tests like transvaginal ultrasound or hysterosalpingography (HSG) were suggested if needed.

20/06/2025

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