Components of Blood
When we receive your donation we separate it into individual components by spinning it in a machine called a centrifuge. The individual components are red cells, white cells, platelets and plasma. These can all be put to different uses.
Red blood cells
The main function of red blood cells is to distribute oxygen to body tissues and to carry waste carbon dioxide back to the lungs.
Red cell transfusions are used to replace heavy blood loss (e.g. trauma, surgery, childbirth) or to correct severe anaemia when the bone marrow is not producing enough red cells (e.g. chemotherapy, leukaemia and thalassaemia). Anaemia is when your haemoglobin levels are lower than normal.
There are of course different ways of treating red cells. Generally, they're all filtered to remove the white blood cells. Red cells are then frozen to be used at a later date. This is actually an extremely expensive and time-consuming process for us, so we only adopt it for rare blood groups.
White blood cells
Seen here are two lymphocyte (left) cells and one neutrophil (right) cell of the human immune system.
White blood cells fight infection and are part of the body’s defence system. White cell transfusions can be given to patients suffering from life-threatening infections whose normal defence mechanisms don’t seem to be responding to antibiotics.
Platelets
Platelets, or thrombocytes, are a constituent of the blood formed in the bone marrow.
These tiny fragments of cells are crucial in helping your blood to clot. If your platelet level is very low then you may suffer a lot from bruising and bleeding.
Plasma
Everybody thinks that blood is red but the truth is that it's only the red blood cells that make it appear that way. Take them away (and the other cellular components) and you're left with plasma, a yellow coloured fluid that carries all blood cells. We process this to extract other products such as:
- Albumin
This protein is really useful when treating anyone who's been severely shocked or burned, or anyone who's lost large amounts of blood. - Clotting factors
One of the major agents in plasma is Factor VIII. It helps anyone whose blood doesn't clot properly.
Immunoglobulins
These are protective antibodies, generated by your white blood cells, which form when you're recovering from an infection or have received some immunisation. These antibodies, once formed, protect you against future attack of the infection.
Specific immunoglobulins contain specially selected antibodies, chosen to treat a specific infection.
For example, donors who have had chicken pox will have high levels of chicken pox antibodies. So their plasma will be ideal for children with leukaemia who have been exposed to chicken pox, and also to prevent any potentially life-threatening diseases.
And then there's the anti-D immunoglobulin which is given to pregnant women.
If an RhD negative woman is pregnant with an RhD positive baby, some of her baby’s blood may enter her system during birth. This may cause the mother to produce anti-D (or anti-RhD) antibodies. And if her next baby happens to be RhD positive, the mother’s anti-D antibodies will attack her baby’s red blood cells. This can be neutralised by giving her an anti-D immunoglobulin injection straight after the birth of her first baby.
Save more lives
Join the organ donor register
Donate platelets
The British Bone Marrow Registry
Donate tissues
Donate cord blood
Every year the lives of thousands of people are saved or transformed through organ transplantation. more information.
Platelet donations are often life-saving. Have you given blood before? You may be able to donate platelets. more information.
Tissue donation gives many families the option of making a difference to others. more information.
In creating one life why not save another? Are you pregnant and live in North London? You may be able to donate cord blood. more information.
Amazing Stories
It took 33 units of blood and skilled medical care to save Mike Austin’s life...
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