MadSci Network: Biochemistry

Re: what is the exact procedure to estimate the amount of iron in blood?

Date: Fri Aug 25 20:41:54 2006
Posted By: Matthew McConeghy, Professor of Science
Area of science: Biochemistry
ID: 1154011382.Bc

Hi Aparna,

Well, the tests to check iron in the blood are not hard to carry out, but they are VERY hard to interpret. There are so many factors that can impact the values for blood cell and chemistry diagnostics!

Here is a quick answer...

The Copper sulfate test is a screening test for anaemia which is used in many places to exclude people from donating blood if their blood iron levels are too low. Also, it is used to identify anemia in pregnancy in order to improve the chances of a good outcome for the mother and child. Here is a good research article from Sri Lanka explaining exactly how it has been done and why it is used. Without knowing more about your project, I don't think I can say too much more than this article says.

Most of the iron in blood is contained in the red blood cells, so the easiest way to determine iron content is to do a hematocrit. Hematocrit is a measure of the proportion of the blood that is made up of red blood cells. The hematocrit varies quite a lot depending on the gender, age, recent history, etc. of the patient, and low or high hematocrit can be a general indication of anemia (too few red blood cells/ too little iron) or hematochromatosis (too much).

In former times, hematocrit was measured by drawing a fairly large sample of blood from a patient and centrifuging it until the cells were separated and the proportion of red blood cells could be directly observed and measured in a graduated test tube. A modern modification of this technique can be done with very small quantities of blood if a specialized, high speed centrifuge is used. There are obvious dangers involved in drawing human blood -- risk of infection, injury to the patient from the needle, hematoma, etc. So, I cannot recommend hematocrits of humans as a procedure for a school lab. It should be done in a clinical setting only, under the direct supervision of trained medical professionals. If you had a sheep or goat and access to a good centrifuge, you could probably do this without much risk or discomfort to the animal, once you had a training from your local physician or laboratory technologist. No humans, though, without direct supervision by an M.D. or fully trained laboratory professional. Drawing blood from humans is NOT a school activity!

In sophisticated medical labs with modern equipment, there are diagnostic machines which directly measure the rbc counts in blood and deliver a computer generated report on number and size of the cells without direct human observation of the cells.

Here is a link to a brief hematocrit article at the USA National Library of Medicine

Iron that is not actually within the red blood cells is usually associated with a protein called serum ferritin. The immunoassay test for measuring ferritin and calculating the amount of iron it is carrying requires some complex test kit materials, analtytical equipment (eg spectrophotometers) and meticulous lab technique. Even if you had the equipment, you could spend a lot of money practicing this repeatedly before you got the experience for reliable, repeatable results.

There are MANY complications to doing any kind of study related to blood iron levels. Many disease states directly and rapidly influence blood cell and chemistry values. Here is a note from a pharmaceutical company that lists some of the routinely encountered factors that can make blood values hard to interpret.

This is why it is hardly ever appropriate to make a diagnosis from a single blood sample, because of the all the factors that cause variations in the values, you have to have multiple samples taken over a period of days or weeks or even months.

Dr Matt McConeghy

Current Queue | Current Queue for Biochemistry | Biochemistry archives

Try the links in the MadSci Library for more information on Biochemistry.

MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci

MadSci Network,
© 1995-2006. All rights reserved.