Preparation of Washed Red Blood Cells Virtual Lab Simulation

General Aim

Washed red blood cells are red blood cells which have had most of the plasma, platelets and white blood cells removed and replaced with saline or another type of preservation solution. Suspension of washed red cells is needed for all haemagglutination tests.

Method

A fresh fowl is bled directly from the heart under aseptic conditions. Collect 2 ml of blood with a syringe in a centrifugation tube with anticoagulant (citrated tube). The citrated blood is centrifuged for 10 minutes at 2500 rpm. The supernatant fluid is discarded. The compact RBCs are shaken with sterile normal saline solution. Then, centrifuged for 10 minutes at 2500 rpm. The supernatant fluid is discarded again. The RBCs are washed once more with normal saline solution. Then, centrifuged at the same rate (2500 rpm) for 15 minutes. After final centrifugation, remove the supernatant without disturbing the pellet. Lastly, 0.1 ml of RBCs are suspended in 9.9 ml normal saline solution to obtain 1% RBCs suspension by volume. Finally, store in a refrigerator at 4 °C till use.

Learning Objectives (ILO’s)

• Become proficient at performing preparation of washed RBCs consistently and accurately.

• Student will learn the essential concepts of haematological tests.

Theoretical Background/Context

Washed red blood cells are red blood cells which have had most of the plasma, platelets and white blood cells removed and replaced with saline or another type of preservation solution.

The most common reason for using washed red blood cells in transfusion medicine is to prevent the recurrence of severe allergic transfusion reactions that do not respond to medical treatment. The usual cause of these allergic reactions is proteins in the donor plasma. These proteins are removed by the process of washing the red blood cells.

There are multiple methods of washing red cells. These can include automated or manual methods. They can use centrifugation or centrifugation-free methods. The red cells can be re-suspended in saline or other types of special preservative solutions for red cells e.g. SAG-M.
 
Uses:

1. Prevention of recurrence of severe allergic reactions.
2. Reduction in transfusion-related complications.
3. Haemagglutination tests.

Principle of Work

A red cell suspension is a common reagent used for many serologic procedures. Red cell suspensions provide the appropriate serum to cell ratio to allow for grading and interpretation of tests results.