BD Vacutainer® CPT™ Cell Preparation Tube with Sodium Heparin

Limitations

Volume of Blood

The exact quantity of blood drawn will vary with the altitude, ambient temperature, barometric pressure, and venous pressure. The minimum volume of blood that can be processed without significantly affecting the recovery of mononuclear cells is approximately 6.0 mL. However, hematological parameters such as a low hematocrit or a low mean corpuscular hemoglobin concentration may also adversely affect product performance, with increased red blood cell contamination above gel barrier.

Temperature

Since the principle of separation depends on a density gradient, and the density of the components varies with temperature, the temperature of the system should be controlled between 18-25° C during separation.

Centrifugation

Since the principle of separation depends on the movement of formed elements in the blood through the separation media, the "RCF" should be controlled at 1500 RCF to 1800 RCF. The time of centrifugation should be a minimum of 15 minutes. (As noted in the trouble shooting section, some specimens may require up to 30 minutes for optimal separation.) Centrifugation of the BD Vacutainer® CPT™ Tube up to 30 minutes has the effect of reducing red blood cell contamination of the mononuclear cell fraction. Centrifugation beyond 30 minutes has little additional effect. The BD Vacutainer® CPT™ Tube may be recentrifuged if the mononuclear "band" or layer is not disturbed.

Time

Blood samples should be centrifuged/separated within two hours of blood drawing. Red blood cell contamination in the separated mononuclear cell fraction increases with longer delays in sample separation. Mononuclear cell recovery decreases with increased time delay before centrifugation.

Cell Separation

As with other separation media, density gradient separation using BD Vacutainer® CPT™ Tubes may alter the proportion of some lymphocyte subsets (e.g., T and B cells) from those in unseparated whole blood (4,5). This alteration is believed to be relatively insignificant in normal cases. However, in cases where the subject is leucopenic or lymphopenic, the selective loss of one subset may alter proportions significantly.

Certain disease states and/or drugs may also alter cell density and therefore affect separation using BD Vacutainer® CPT™ Tubes(6).

Microbial Contamination

Microbial contamination of reagents may alter the results obtained on cells separated using BD Vacutainer® CPT™ Tubes.

Separated Cell Assays

For determinations other than those described in the results section, for which specimens are separated using BD Vacutainer® CPT™ Tubes, a user should establish to his or her satisfaction that the values obtained meet his or her criteria for clinically acceptable values.

Platelet Contamination

Repeatability studies indicate that mononuclear cell samples separated by the BD Vacutainer® CPT™ Tube method have approximately 1.5 times the platelet concentration that a matching sample separated by the FICOLL™ HYPAQUE™ method contains before the samples are "washed" by subsequent centrifugation steps.

FICOLL is a trademark of Amersham Biosciences AB
HYPAQUE is a trademark of Amersham Health AS