Artefactual elevation of an automated white cell count following femoral vein puncture.

We report the novel occurrence of an erroneous automated total and differential white blood cell count on a blood sample obtained by traumatic femoral venepuncture, caused by contamination of the blood sample with subcutaneous adipose tissue. The erroneous counts were observed on a Bayer-Technicon H2 analyser while counts on a Coulter GenS, were much less affected. Characteristic scatter plots from both instruments are illustrated.