What is the main advantage of doing a blood smear rather than an automated CBC?

Unlike automated tests (such as a CBC), a technician or healthcare provider looks at a blood smear under the microscope in order to detect a wide range of changes that give clues to underlying diseases.

What could cause an automated cell counter to malfunction?

Using cell densities that are too low or too high is generally associated with counting errors, specifically with a traditional hemocytometer. In the situation where the cell density is too high, cells may aggregate and lead to egregious counting errors.

What is difference between CBC and blood smear?

You may need a blood smear if you have abnormal results on a complete blood count (CBC). A CBC is a routine test that measures many different parts of your blood. Your health care provider may also order a blood smear if you have symptoms of a blood disorder.

What are the principle of automated blood cell counter?

Modern automated hematology instruments use either optical methods (light scatter), impedance-based methods based on the Coulter principle (changes in electrical current induced by blood cells flowing through an electrically charged opening), or a combination of both optical and impedance-based methods.

Why is it important to smear the blood as soon as the drop is placed on the slide?

Common Causes of a Poor Blood Smear • As soon as the drop of blood is placed on the glass slide, there should be no delay in the making of the smear. Any delay, whatsoever, results in abnormal distribution of the white cells with many of the white cells accumulating at the thin edge of the smear.

Why is a good blood smear is necessary for accurate counts?

From the clinical standpoint, blood smear examination serves 3 important objectives. First, it serves as a quality control tool in verifying the results generated by the automated analyzers. Second, it allows for identification of abnormal/immature/atypical cells, if present.

Why manual RBC count is unreliable?

Manual counting relies on human visualization, a feature that is susceptible to inaccuracies from time to time. In the situation where the concentration is too high, cells may aggregate and lead to egregious counting errors.

Why is manual cell count necessary?

Manual cell counting offers an accessible way to determine the concentration of cells in a liquid sample, requiring just a light microscope and hemocytometer. Cell viability can be calculated by treating the cell suspension with cellular dyes, such as Trypan Blue.

Why would my doctor order a blood smear?

A blood smear is often used as a follow-up test to abnormal results on a complete blood count (CBC) to evaluate the different types of blood cells. It may be used to help diagnose and/or monitor numerous conditions that affect blood cell populations.

Is blood smear the same as differential?

The differential staining allows one to identify the types of white blood cells on the smear. The smear review is performed same as manual differential but rather than quantitating the different types of cells the technologist will look for abnormal cells and semiquantitate (few,moderate,many) if present.

What are the advantages of automated cell counter?

Existing automated cell counters have the advantage of largely removing human subjectivity from the cell counting workflow. They are also often faster than counting manually and can count a larger number of cells, increasing statistical accuracy.

How do automated cell counters work?

Automated cell counters are machines that automatically count cells. The sample is loaded into an automated cell counter and it is forced through a small tube while the automated cell counter uses optical or electrical impedance sensors to count how many cells go through the tube.

Is it possible to do an automated differential blood count?

With the development of more sophisticated, automated blood cell counting instruments, it has now become routine to provide an automated differential.

When is a blood smear indicated in a blood test?

However, if the results from an automated cell count and/or differential indicate the presence of immature, atypical, or abnormal white blood cells (WBCs), red blood cells (RBCs), and/or platelets or if there is reason to suspect that abnormal cells are present, then a blood smear may be performed.

What is the difference between a blood smear and CBC?

The blood smear is primarily ordered as a follow-up test when a CBC with differential, performed with an automated blood cell counter, indicates the presence of atypical, abnormal, or immature cells.

What do red blood cells look like in a smear?

They are round and flattened like a donut with a depression in the middle instead of a hole (biconcave). Due to the hemoglobin inside the RBCs, they appear pink to red in color with a pale center after staining the blood smear.