- Gold sodium thiomalate as currently used is a mixture probably consisting of small polymers of different structures. The colourless and yellow solutions have been studied in platelets, which had been known to show biological effects of the yellow solution. Only the yellow solution causes ADP dependent platelet aggregation. Platelets treated with the yellow solution contain larger particles (100-700 nm in diameter) compared to a maximal particle size of 40 nm from the colourless solution. The biological differences observed may be due to phagocytosis of the larger components with resultant ADP release and aggregation.