Marathon runners are scrawny individuals, the best of whom tell stories of running to school in the highlands of East Africa (high altitude breeds lungs better able to supply red blood corpuscles).
The remains of these corpuscles are removed using a centrifuge.
It is thus that the daughters of a liver cell, say, inherit the property of liverness and so do not turn into kidney cells or blood corpuscles.
The government's BSE advisory committee looked into blood-disposal methods in 1996, at the height of the public health panic, and saw no problem in sending surplus corpuscles down the drain.
The Fibre Array Scanning Technology (FAST) cytometer, developed in conjunction with the Scripps Research Institute, uses an array of optical fibres and a laser beam instead.The sample to be examined is first treated with a chemical that destroys the red blood corpuscles it contains.
It is therefore possible to disrupt the adult corpuscles from the mother's blood without affecting the fetal ones.
This is necessary because 99% of the cells in blood are red corpuscles, and they confuse the picture.The remaining cells (mostly white cells of various sorts) are then treated with a chemical that marks the ones that are of particular interest.
IF TRADE is the lifeblood of the world economy, then the ships that perform the mundane task of transporting goods and raw materials from where they are produced to where they are wanted are the red corpuscles.
That means it may be possible to replace amniocentesis with a simple blood test.In this case the red blood corpuscles, far from being a nuisance, actually provide the data.
And there are now antibody-based markers that will detect signs of Down's syndrome, cystic fibrosis and sickle-cell anaemia in such fetal corpuscles.
In a real kidney, part of the aqueous fraction of blood is squeezed out of it in filters called glomeruli, leaving blood corpuscles, platelets and dissolved proteins behind to be returned to the bloodstream.
