Veterinary Clinical Pathology Laboratory

Tips for Best Sample Preparation

For Whole Blood Samples (Complete Blood Count, Platelet Count)

We recommend the use of EDTA rather than heparin for increased stability of the sample submitted for whole blood count. There are several types and sizes of blood tubes available to acquire samples and as the blood volume needed for these tests is very low and the volume of blood that may be obtained from some animals such as mice is also low, it is best to invest in size appropriate blood tubes for your analyses. If this is the first time that you are acquiring this type of sample, please inquire with the laboratory so that we may provide some small blood tubes for your use. After acquiring the sample, please mix the tube well to prevent clot formation. If the sample is to be analyzed within 24 hours, please store it at room temperature. If delayed, consider also making a peripheral blood smear on a microscope slide.

For Serum Samples

Like the whole blood samples, it is best to use size appropriate blood tubes for sample collection. Many small tubes are available with gel separators to aid in the preparation of the sample. Make sure to let the sample adequately clot for at least 15 minutes before centrifugation. Centrifugation time and speed can affect your results so make sure you make this part of your standard protocol if you are collecting many samples over a period for your research project. Also, try to prevent hemolysis in your samples by promptly centrifuging them and not using too small of a needle for sample acquisition. If you choose to use a gel type tube, transfer the serum to a storage vial to prevent other changes in your analytes. Freezer type tubes (with o-ring enclosure) are especially good. Samples should be analyzed within 24 hours and can be refrigerated. Prolonged storage should be at -70°C although it should be acknowledged that freezing samples may also alter some results.

For Plasma Samples

Heparinized plasma can also be used for biochemistry determinations. If sample volume is potentially a problem and you desire both a CBC and chemistry, one tube can be submitted to the laboratory. Like the whole blood samples, it is best to use size appropriate blood tubes for sample collection. Many small lithium heparin tubes are available with gel separators to aid in the preparation of the sample. Centrifugation time and speed can affect your results so make sure you make this part of your standard protocol if you are collecting many samples over a period for your research project. Also, try to prevent hemolysis in your samples by promptly centrifuging them and not using too small of a needle for sample acquisition. If you choose to use a gel type tube, transfer the serum to a storage vial to prevent other changes in your analytes. Freezer type tubes (with o-ring enclosure) are especially good. Samples should be analyzed within 24 hours and can be refrigerated. Prolonged storage should be at -70°C although it should be acknowledged that freezing samples may also alter some results.