The precise and effective counting of blood cells is essential in medical laboratory science for the diagnosis and ongoing monitoring of a variety of hematological disorders. A cutting-edge tool created to expedite this procedure, the Automated Cell Counter Hematology Analyzer provides accuracy, speed, and dependability.

What is Automated Cells Counter – Hematology Analyzer

An automated cell counter or hematology analyzer is a laboratory instrument used to analyze blood samples by counting and characterizing blood cells, including red blood cells (RBCs), white blood cells (WBCs), and platelets. It provides rapid, accurate, and standardized blood test results essential for diagnosing and monitoring various medical conditions.

Complete Blood Counts (CBC) form the main bulk of laboratory tests requested. By manual method, it is difficult to do all of these with acceptable accuracy and precision. This was realised very early. In 1956, Wallace Coulter first described an electronic cell counter, which has revolutionized the hematology laboratory known as Backman Coulter

Since then tremendous technological improvements have occurred in electronic blood cell counting and sizing. The market is now flooded by myriad of such instruments. The manufacturers have tall claims for these, which have to be verified before making a decision for purchase. Hematology analyzers are now available for the needs of laboratory of any size. The range varies from simple blood cell counts and red cell indices to partial or full differential count, histograms of cell sizes and reticulocyte count. It is important, particularly in our country, to ensure that proper after-sale services and spares are available with the supplier.

Presentation: Lectures Automated Cells Counter

Types of Automated Cell Counters

Fully automated instruments

In a fully automated cell counter, an appropriate blood sample volume is presented to the instrument. Some instruments are accomplished to aspirate the blood sample themselves from tubes already placed on a sample rack or similar device.

Semi-automated instruments

Semi-automated cell counters require some steps, e.g., dilution, to be performed by the operator, and some steps are carried out manually. They often measure a small number of components. These are mostly outdated now.

Principles of Automated Blood Counting

Measurement of haemoglobin concentration

Most automated counter instruments measure hemoglobin (Hb) by modifying the traditional cyanomethaemoglobin method. Because these instruments have a high throughput, they take absorbance measurements at specific time intervals after the blood has been mixed with the active reagents but before the reaction concludes. To facilitate this, the standard HiCN technique is adjusted regarding the reaction’s pH, temperature, and reagent concentrations. Typically, a non-ionic detergent is employed to promote rapid cell lysis and minimize turbidity. Alternatively, some instruments utilize sodium lauryl sulfate to measure hemoglobin, as the cyanide used in the HiCN method is highly toxic.

2. Particle (Cell) Counting

The two primary types of technologies employed for counting blood cells are electrical impedance counting and optical (light scattering) counting methods. These techniques enable the rapid counting of a large number of cells. As a result, they provide a high degree of precision and consistency, which significantly differs from the outcomes achieved through manual blood cell counting methods. These technologies have enhanced the clinical significance of RBC count, MCV, and MCH.

a. Aperture impedance counting

Blood cells inhibit the flow of electrical current, meaning they obstruct the passage of electrical current. There are specific diluents that permit electrical current to flow through them. This distinction is the foundation for cell detection in this technology. The cells are significantly diluted in a buffered electrolyte solution.

This liquid moves through a narrow opening. A steady current runs through two electrodes positioned on either side of it. When a blood cell moves through, the electrical conductance in the opening drops. This produces an electrical signal that is proportional to the size of the blood cell. These signals are electronically processed and separated to count white blood cells, red blood cells, and platelets.

b. Optical method (light scattering) counters

The blood cells scatter light to varying degrees and at different angles, depending on factors such as their size, shape, nuclear lobes, and the presence of granules. This principle underlies the detection and counting of blood cells using electro-optical techniques. The blood cells are appropriately diluted.

The diluted suspension of blood cells is designed to flow through an opening in a manner that allows the cells to pass individually in front of a light source. The light is scattered by the cells. This scattering is detected by a photomultiplier tube (PMT) or photodiode, which transforms it into an electrical impulse. These impulses are subsequently organized to count WBCs, RBCs, platelets, and provide a three-part differential analysis (neutrophils, lymphocytes, and unidentified cells).

3. Automated WBC differentials

Certain automated blood analyzers possess the ability to perform WBC differential counting and can offer three, five, or seven part WBC differential results. Unusual cell populations might be highlighted for verification through microscopy. Three part differential counts are determined based on the different volumes of various cell types. In optical detection techniques, this can be enhanced using flow cytometry. In electrical impedance methods, cells are additionally characterized with radio frequency currents or low and high frequency electromagnetic currents. Some analyzers utilize cytochemical stains to distinguish between different types of WBC.

4. Platelet counting

Platelets can be quantified in whole blood using the same methods that are utilized for counting red blood cells. Typically, the platelet count is performed in the same channel as red blood cell detection, with a threshold established to distinguish platelets from red blood cells.

5. Reticulocyte counts

Reticulocytes possess RNA. There are both fluorescent and conventional dyes that interact with RNA, allowing for the counting of reticulocytes.

Uses of Automated Cell Counters

• Complete Blood Count (CBC) Analysis: Measures RBC, WBC, hemoglobin, hematocrit, and platelet count.
• Disease Diagnosis: Helps in detecting infections, anemia, leukemia, and other hematological disorders.
• Monitoring Treatment Response: Assists in tracking patient responses to chemotherapy, bone marrow transplants, and other treatments.
• Blood Donation Centers: Ensures donor eligibility based on hemoglobin levels and other parameters.

Comparison: Automated vs. Manual Cell Counting

Feature	Automated Cell Counting	Manual Cell Counting
Accuracy (variability)	High, with minimal variation	Subject to human error
Speed (labor-intensive)	Fast, processes multiple samples quickly	Slow, requires individual slide examination
Differentiation	Detailed WBC, RBC, and platelet indices	Basic classification
Cost	Expensive due to equipment and reagents	Low-cost, requires only a microscope and stains
Morphological Assessment	Limited; requires additional microscopic examination	Detailed, allows assessment of cell shape and abnormalities
Skill Required	Minimal training needed	Requires skilled technicians