Manual RBCs count using Neubauer Chamber

Introduction

Counting red blood cells (RBCs) using a Neubauer chamber, also known as a hemocytometer, is a manual technique commonly used in hematology. Here’s a step-by-step guide on how to perform a manual RBC count using a Neubauer chamber:

Equipment and Materials

1. Neubauer chamber
2. Microscope
3. Coverslip
4. Hemocytometer pipette
5. Diluting fluid (usually a diluent like Hayem’s or normal saline)
6. Blood sample

Procedure

1. Prepare the Dilution:
   • Mix a small amount of blood with a diluting fluid. The dilution factor will depend on the specific protocol and the expected concentration of RBCs. A common dilution factor is 1:200.
2. Load the Hemocytometer:
   • Using a hemocytometer pipette, carefully load a small amount of the diluted blood into the hemocytometer. Allow the fluid to fill the chamber through capillary action.
3. Allow the RBCs to Settle:
   • Allow the RBCs to settle for a few minutes to ensure an even distribution across the counting area.
4. Microscopic Examination:
   • Place the loaded Neubauer chamber on the microscope stage. Using the low-power objective (usually 10x), locate the counting grid.
5. Counting RBCs:
   • Count the RBCs within the specified counting areas (usually the four large corner squares) using the high-power objective (usually 40x).
6. Calculations:
   • Calculate the RBC count per microliter (µL) using the formula:

1. The depth factor for a Neubauer chamber is 0.1, and the volume of one large square is 1 mm².
2. Repeat the Process:
   • Perform the counting in multiple squares and calculate the average for accuracy.
3. Clean the Chamber:
   • Clean the Neubauer chamber thoroughly with distilled water and dry it before the next use.

Keynotes on Manual RBCs count

• Precision is crucial, so take your time during counting and ensure the Neubauer chamber is clean.
• Always follow safety protocols when handling blood samples.
• Consult the laboratory’s standard operating procedures (SOPs) for specific guidelines.
• This technique provides an estimate of the RBC count and is a valuable tool in hematology. Always consult with healthcare professionals or laboratory experts for accurate and reliable results.