TC-99(M)-PHENYLENE IMINE PHENOL AS A POTENTIAL LEUKOCYTE LABELING AGENT

The aim of this study was to evaluate Tc-99(m)-labelled phenylene imin e phenol (Tc-99(m)-Ph(IP),) as a leukocyte label. The Tc-99(m) complex exhibits a neutral lipophilic character. The radiochemical purity of the Tc-99(m)-Ph(IP)(2) was high both soon after labelling (94.5 +/- 1. 2%, n = 7) and at 24 h (89.7 +/- 1.0%, n = 7). In a comparative study, the labelling efficiency of Tc-99(m)-Ph(IP)(2) and Tc-99(m)-hexamethy lpropylene amine oxime (Tc-99(m)-HMPAO) labelled leukocytes was 47.1 /- 3.5% (n = 7) and 58.5 +/- 7.0% (n = 7) respectively. The viability of labelled leukocytes was greater than 90% for both Tc-99(m) complexe s. The elution ratios of labelled leukocytes with Tc-99(m)-Ph(IP)(2) a t 1, 4 and 24 h were 10.1 +/- 3.5%, 17.2 +/- 2.7% and 23.0 +/- 2.4% (n = 7) respectively, while those with Tc-99(m)-HMPAO were 10.8 +/- 1.2% , 18.3 +/- 2.0% and 37.0 +/- 3.7% (n = 7) respectively. Ln conclusion, Tc-99(m)-Ph(IP)(2), with good stability and significant leukocyte lab elling efficiency, is a potential leukocyte label.