Content area
Full text
TO THE EDITOR: The recent letter on fractionated cold-kits by Decristoforo and Riccabona (I) was interesting. It was surprising to note the unexpected high rate of failure with fractionated MAG3 kit after storage for 6 days, especially when eluate from different generators were used.
We have been using fractionated MAG3 for the last 3 yr without a single incidence of failure. A whole MAG3 kit was reconstituted in 2.6 ml of saline for injection and fractionated into five aliquots (0.5 ml) in N^sub 2^ -filled Amersham vials using 27 G insulin syringe. These vials were stored in -20degC freezer. The fractionated kits were reconstituted with 600-1300 MBq of ^sup 99m^ Tc-pertechnetate in 1.5 ml saline (final volume 2.0 ml), boiled for 10 min and cooled for 15 min before use. The radiochemical purity was >96% on the day of fractionating or after storage at -20degC for 2 yr.
The rapid fall in the radiochemical purity from 97% to 63.6% +/-48% within 6 days of storage at - l OdegC was surprising as described by Decristoforo and Riccabona (I ). The problem might be attributed to high volume of saline (2.5 ml) in the fractionated kit; 0.5 ml aliquots seem to offer better stability over a 2-yr period of storage. The...