Formation of labelled colloid in 99Tcsup(m)-DMSA due to the presence of bactericidal fluid

The possibility that traces of bactericidal fluid in 99Tcsup(m)-DMSA could lead to the formation of labelled colloid, was explored. In vitro investigations were undertaken using ultracentrifugation techniques and photon correlation spectroscopy. The latter showed that both contaminated and uncontaminated DMSA contained colloidal (or particulate) material. However the presence of 10 μl bactericidal fluid as contaminant was shown by ultracentrifugation to result in labelling of this colloidal material when 99Tcsup(m) was added to DMSA. Studies in a normal volunteer confirmed the results of the in vitro studies, in that significant liver and spleen uptake was observed after the administration of contaminated 99Tcsup(m)-DMSA. (author)