Is Your Blood Sample Being Handled And Processed Correctly?

Posted on February 10th, 2014

Over the years, it has become quite evident that different veterinary and human laboratories may have different range values for various segments and components that reside in blood serum. This will definitely relate to all enzymes, organ secretions, hormones and antibody levels that occur in a blood serum sample. The accuracy of these levels will always depend on how the sample is handled.

For proper accuracy, the sample must be kept cool and run in a cooled state otherwise the test levels will be usually elevated and inaccurate. Major differences in test results will definitely occur based upon how the temperature of the sample is handled between in-house laboratories and other outside laboratory facilities.

It is not your job to merely accept the fact that the sample taken from you or from your pet is immediately refrigerated and kept in a cooled state as it is being processed. Without having this done, a test result will be inaccurate. Obviously, improper centrifuging and fracturing red blood cells by using too small a needle will also cause test results from blood serum to be inaccurate.

For many years, I found by sending my blood samples and the samples of my patient’s bloods to various human and veterinary laboratories for processing, a huge discrepancy occurred between the blood serum test results.

The following procedures, beside those procedures listed above, must be done correctly in order to receive accurate blood serum test results.

Once the blood sample is taken, the serum must be spun down immediately and then refrigerated. Leaving the spun down sample in the centrifuge for too long will allow the sample to reach room temperature and invalidate the blood serum test results.

If the sample is left unrefrigerated while waiting for an outside laboratory to pick-up the blood serum sample, this will also invalidate the test results. NOTE: Most laboratory pick-ups of blood samples are kept in a refrigerated state as they are being transported to their laboratory of destination.

Once the serum sample reaches the laboratory, it must remain cool until it is processed in that cooled state. The sample cannot sit at room temperature while waiting for other serum samples to reach the laboratory so they can all be processed at one time in a batch.

If the sample is stored in a cooled state, the rubber stopper should not be removed while storing the sample because without the stopper being left in place, even in a cooled place, evaporation can occur, causing invalid blood serum test results.

This is very critical in general, but particularly critical when I have my endocrine immune blood serum samples processed because most of my referral patients are usually critical and an inaccurate blood serum test result can be catastrophic for them!

I have the samples overnighted on blue ice in a refrigerated state to National Diagnostic Laboratories in Texas, because they not only demand this type of care of the blood serum sample in order to obtain accurate test results, but they are the only veterinary laboratory that has the ability to process a total estrogen test.

The following is a chart, created by a human European laboratory that also believes as I do as well as the head of National Diagnostic laboratories. This chart indicates the various increases in the test results using one ovarian hormone called Estriol subjected to different temperatures. This chart should give you a definite idea as to how blood serum test results can change with temperature variations. NOTE: temperatures are in Celsius.

Estriol (One of three estrogen hormones produced by the ovaries)

Not in pregnancy < 0.6 ng/ml
Up to 20° sett.     16.5-36.5 ng/ml
21°- 25° sett.      49.2-87.0 ng/ml
26°- 30° sett.      58.6-120.0 ng/ml
31°- 32° sett.      52.2-130.0 ng/ml
33°- 34° sett.      54.7-147.0 ng/ml
35°- 36° sett.      75.7-246.0 ng/ml
37°- 38° sett.      99.0-315.0 ng/ml
39°- 40° sett.      161.0-375.0 ng/ml
41°- 42° sett.      104.0-322.0 ng/ml

I am told by Jason McDonald, the head of National Diagnostic Laboratories, that most blood serum test kits will contain a schedule of different temperatures and different values that will be printed on most blood serum test kits. However, it appears that most laboratories do not follow these printed schedules very closely and apparently are not aware at this time of how temperature variations can yield wide variations with most blood serum test results and that is why often there can be a huge discrepancy in test results between different laboratories.

I think you should question your veterinarian and/or physician when you have a blood test taken and make sure they are aware of the fact that the sample needs to be kept refrigerated and processed in a refrigerated state, otherwise the test results will be inaccurate and will be of little value for your healthcare professional, who is trying to treat that specific disease.

These are just some of my thoughts and I do hope they help make a difference.