We evaluated the performance of an automated 48 detector KinetiCount gamma counter using solid phase reagents for total thyroxin (TT4) and free thyroxin (FT4). Interassay coefficients of variations (CV) for both total T4 and free T4 ranged from 5.4% to 13%. Between-method correlation coefficients were 0.9798 for TT4 and 0.8844 for FT4. Detection limits for TT4 and FT4 were 3 μg/l and 3 ng/l, respectively. TT4 was linear up to 200 μg/l. The recovery of TT4 was between 99 to 101%. A computer-stored standard curve for total T4 was stable over a 6-day period. The 48 counting chambers demonstrated stability over a 45-day period with no significant changes in counting efficiency (p > 0.05). Precision between the 48 chambers gave a CV of 1.6%. Crosstalk between chambers was <0.3% with count rates up to 80,000 cpm. We conclude that the KinetiCount immunoassay system using solid phase separation technology performs well and is suitable for routine clinical use.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Nuclear Medicine|
|State||Published - Dec 1 1986|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging