1. Basic Understanding of Blood

2. Blood-Smear-Test• Preparation

• Fixation• Staining

Clinical DiagnosticLukas K.3rd academic yearOctober 2016

Blood is soup

Liquid portion

Vegetables- Water

- Salts (electrolytes)- Small proteins- Antibodies

- Red blood cells- White blood cells- Platelets

These cells are produced in the bone marrow from larger,

more complex progenitor cells.

Through a series of divisions, these larger cells are transformed into red blood cells,

white blood cells, and platelets

Stem cell

Lymphoid Stem Cell

Myeloid Stem Cell

Resting & Activated Platelet

Lymphocyte

Monocyte

Neutrophil

Erythrocyte RBC

WBC

Series of divisions transforms complex cells into red blood cells,

white blood cells, and platelets

Stem cell can become any red/white blood cell

Stem cell

Resting & Activated PlateletLymphocyte

Monocyte

NeutrophilErythrocyte

Immunology

Immunology

Immunology

Immunology

Immunology

What Is a Blood Smear? A blood smear is a blood test used to look for abnormalities in

blood cells. The three main blood cells that the test focuses on are:

•white cells, which help your body fight infections

The Vegetables

•red cells, which carry oxygen throughout the body

•platelets, which are important for blood clotting

White Blood Cell

Each cell type has a specific function in the body. The forms of the cells

are specialized to handle these functions.

Red Blood Cell

Platelet

Electro Microscop

y

What has the shape of the cells to do with the blood smear test?

Number of Blood cells Shape of Blood cells

Blood-Smear-Test is a very cheap and easy blood examination test and is done in sveral minutes, he basically provides us simple information of

which can ”help” doctors diagnose certain blood disorders or other medical conditions.

Let´s have a look at the Blood Smear Test

Blood Smear Test

PreparationFixation Staining

Includes 3 steps

2. Fixation of Blood Smear

To preserve the morphology of the cells, films must be fixed as soon as possible after they have dried.

Why do we fixate blood smears?

It is important to prevent contact with water before fixation is complete.

Methyl alcohol (methanol) is the choice, although ethyl alcohol ("absolute alcohol") can be used.

Methylated spirit (95% ethanol) must not be used as it contains water.

Different fixativesMethyl alcohol

(methanol) is the

choice,.

although ethyl alcohol ("absolute alcohol") can be

used

Can you distinguish between a good done blood smear from a bad one?

Let´s compare some

The shape of blood film

Qualities of a Good Blood Film

It should not cover the entire surface of slide.

It should have smooth and even appearance.

It should be free from waves and holes.

It should not have irregular tail.

Want to change thickness of Blood Smear?

1. The angle of the spreader slide. (the greater the angle, the thicker and shorter the smear).

2. Size of the blood drop.3. Speed of spreading.

Notes:4. If the haematocrit increased, the angel of the spreader slide

should be decreased.5. If the haematocrit decreased, the angel of the spreader slide

should be increased.

large angle

low HCT

small angle

high HCT

Parts of Blood SmearA peripheral blood film consists of 3 parts :

1. Head: the portion of blood film near the drop of blood.2. Body: the main part of the blood film.3. Tail: the tapering end of the blood film.

Common cause of a poor blood smear:

1. Drop of blood too large or too small2. Spreader slide pushed across the slide in a jerky manner3. Failure in keep the entire edge of the spreader slide against the slide

while making the smear4. Failure in keep the spreader slide at a 30 ⁰ angel with the slide5. Failure to push the spreader slide completely across the slide6. Irregular spread with ridges and long tail: edges of spreader dirty or

chipped ; dusty slide7. Holes in film – slide contaminated with fat or grease and air bubbles8. Cellular degenerative changes: delay in fixing inadequate fixing time

or methanol contaminated with water

A. Blood film with jagged tail made from a spreader with achipped end.

B. Film which is too thick C. Film which is too long, too wide, uneven

thickness and made on a greasy slide.D. A well-made blood film.

Examples of unacceptable smears

Biologic causes of a poor smear

1. Cold agglutinin - RBCs will clump together.Warm the blood at 37° C for 5

minutes, and then remake the smear.

2. Lipemia - holes will appear in the smear. There is nothing you can do to

correct this.

3. Rouleaux - RBC’s will form into stacks resembling coins. There is nothing you can do to correct this.

Even with naked eye a blood smear can already indicate different

physiological conditions of organism

Hope you learned something