What is CSEEL and what does it offer?

CSEEL (Center for Scientific Exploration and Experiential Learning) is a premier Indian STEM educational initiative offering hands-on science experiments, 3D live laboratory simulations, curriculum-aligned project kits, teacher training workshops, and national science conclaves aligned with NEP 2020.

How does CSEEL support NEP 2020 experiential learning?

CSEEL shifts education from rote memorization to active inquiry and hands-on experimentation. Students observe, build, analyze, and apply scientific concepts to real-world challenges, developing critical thinking and scientific temper as envisioned by NEP 2020.

What subjects and classes are covered in CSEEL simulations and experiments?

CSEEL provides comprehensive physics, chemistry, biology, environmental science, and applied robotics experiments and virtual simulations for students from Class 6 through Class 12, mapped to CBSE, ICSE, and state curricula.

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Institutions, teachers, and students can explore live simulations, order DIY lab kits, register for national seminars, and join the CSEEL EduNetwork by visiting https://www.cseel.org.

Identification of Human Blood Cells in Peripheral Smear

Experiment video

What you will learn

Prepare and stain a thin peripheral blood film using Leishman's stain to identify erythrocytes, platelets, and differential leukocytes (Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils).

Materials needed

Prepared sterile human blood smear slide or fresh finger-prick blood via sterile lancet
Prepared sterile human blood smear slide or fresh finger-prick blood via sterile lancet
₹50
What is it?
Leishman's Hematological Stain solution (0.15% in pure acetone-free methyl alcohol).
Specifications
Dye Composition
Methylene blue and eosin Y in pure absolute methanol
Solvent
Acetone-free methanol (serves as fixative and solvent)
Bottle
100 mL amber dropper bottle
Leishman's Stain powder dissolved in absolute methanol (0.15% w/v) bottle
Leishman's Stain powder dissolved in absolute methanol (0.15% w/v) bottle
₹95
What is it?
Certified professionally prepared human peripheral blood smear reference slides.
Specifications
Preparation
Thin blood film, Leishman stained, mounted in DPX under glass coverslip
Quality
Class A hematological teaching slide showing crisp morphology
Distilled water / Sorensen's Phosphate buffer (pH 6.8) mL
Distilled water / Sorensen's Phosphate buffer (pH 6.8) mL
₹140
What is it?
Synthetic non-drying microscope immersion oil (ISO 8036).
Specifications
Refractive Index
nD = 1.515 at 23°C (matches glass)
Viscosity
Low viscosity non-drying formula
Volume
30 mL dropper bottle
Grease-free microscope slides with smooth polished spreader slide
Grease-free microscope slides with smooth polished spreader slide
₹185
What is it?
Standard laboratory apparatus used in Identification of Human Blood Cells in Peripheral Smear.
Specifications
Category
Biology Apparatus
Grade
CBSE / NEP 2020 Laboratory Standard
Compound Microscope with 100x Oil Immersion lens & Cedarwood oil
Compound Microscope with 100x Oil Immersion lens & Cedarwood oil
₹230
What is it?
Standard laboratory apparatus used in Identification of Human Blood Cells in Peripheral Smear.
Specifications
Category
Biology Apparatus
Grade
CBSE / NEP 2020 Laboratory Standard
70% Isopropanol alcohol swabs & sterile disposable lancets set
70% Isopropanol alcohol swabs & sterile disposable lancets set
₹275
What is it?
Standard laboratory apparatus used in Identification of Human Blood Cells in Peripheral Smear.
Specifications
Category
Biology Apparatus
Grade
CBSE / NEP 2020 Laboratory Standard
Staining rack and timer
Staining rack and timer
₹320
What is it?
Standard laboratory apparatus used in Identification of Human Blood Cells in Peripheral Smear.
Specifications
Category
Biology Apparatus
Grade
CBSE / NEP 2020 Laboratory Standard

Tick items as you collect them. Tap + to see the product, specifications and buy options.

Stay safe

Strict aseptic precautions: use disposable lancets once and discard immediately in a sharp-safe container.
The blood smear must have a smooth monolayer 'feathered edge' without ridges or holes.
Buffer pH must be maintained at 6.8 for optimal differential differentiation of granules.
Do not touch slide surface with fingers to prevent lipid smudging.

Steps

0 of 7 steps done

1Clean fingertip with alcohol swab, let dry, and make a quick prick with a sterile lancet.
Observation
Place single drop of prepared blood 1 cm from end of clean grease-free glass slide.
Safety
In school labs, use commercially prepared fixed certified human peripheral blood smear slides.
2Place a small drop of blood 1 cm from the frosted end of a clean slide.
Observation
Place spreader slide at 30° to 45° angle in front of drop; draw back until blood spreads across width; push forward smoothly.
Safety
Make smear in a single continuous rapid stroke without stopping to produce ideal feather edge.
3Hold a spreader slide at a 30°-45° angle, pull back until it contacts the blood drop spreading it along the edge, then push smoothly forward in one stroke to form a thin feathered tail.
Observation
Air-dry smear completely within 30 seconds; fix and stain by covering with Leishman's stain for 2 minutes.
Safety
Cover slide to prevent stain evaporation and precipitation of dye crystals.
4Air dry the blood film completely for 2 minutes.
Observation
Add double volume of buffered distilled water (pH 6.8); mix by gentle blowing; incubate 10 minutes.
Safety
Buffered water pH is critical; acidic water causes red smear, alkaline causes dark blue smear.
5Place slide on staining rack. Cover film with 10 drops of Leishman's stain for 2 minutes (methanol fixes cells).
Observation
Wash under gentle stream of tap water; air-dry vertically; examine under 100× oil immersion objective.
Safety
Apply single drop of synthetic cedarwood immersion oil directly onto dried smear.
6Add 20 drops of distilled water/buffer, blow gently to mix until a metallic golden scum forms, and let stain for 10 minutes.
Observation
Perform systematic zigzag battlement count across feather edge until exactly 100 white blood cells are classified.
Safety
Wipe oil immersion lens clean with xylene lens paper immediately after use.
7Wash gently under running tap water, air dry, add cedarwood oil, and examine under the 100x oil immersion objective.

Tap + on a step to see what you will observe and any safety tips.

Record your observations

Leukocyte (WBC) Type	Nuclear Morphology	Cytoplasmic Granules & Staining	Observed Percentage (%) in 100 WBCs
Neutrophil (PMN)	Multilobed nucleus (3 – 5 connected lobes)	Fine lilac / pale pink neutral granules	64% (Most abundant phagocyte)
Lymphocyte (Small/Large)	Large round darkly stained nucleus filling >90% cell	Scanty rim of clear sky-blue cytoplasm, agranular	26% (Adaptive immune cells)
Monocyte	Large kidney / horseshoe-shaped indented nucleus	Abundant pale grayish-blue cytoplasm, agranular	6% (Precursor to macrophage)
Eosinophil	Bilobed spectacle-shaped nucleus	Coarse bright reddish-orange refractile granules	3% (Allergic / parasitic response)
Basophil	S-shaped bilobed nucleus obscured by granules	Coarse dark purple / blue-black granules	1% (Histamine releasing rare cell)

Tap a highlighted cell to write your own observation.

Result and conclusion

High magnification examination reveals non-nucleated biconcave RBCs, multi-lobed pinkish-purple Neutrophils (~65%), large-nucleus Lymphocytes (~25%), and kidney-shaped Monocytes.

Differential Leukocyte Count (DLC %): Neutrophils 60-70%, Lymphocytes 20-30%, Monocytes 2-8%, Eosinophils 1-4%, Basophils 0.5-1%

Observation	What it means
Normal Differential Leukocyte Profile	Observed WBC distribution falls squarely within physiological healthy human reference ranges.
Neutrophil Polymorphism	Neutrophils display segmented polymorphonuclear lobes (3-5 lobes) diagnostic of mature active microphages.
Leishman / Wright Stain Chemistry	Methylene blue stains acidic nuclear DNA dark violet; Eosin stains basic cytoplasmic hemoglobin and granules bright pink/red.
Absence of Pathological Blasts	Smooth mature nuclear chromatin and absence of immature leukemic myeloblasts confirm normal peripheral hematopoiesis.

Differential Leukocyte Count (DLC) Percentage Distribution

Sample readings. Replace with your own results.

Experiment photos

Before the experimentDuring the experimentResult