| Half-Life in
Plasma
|
Notes:
- To determine the half-life of an analyte in the circulation enter two measured results
in the boxes above and the time in hours between the measurements.
- Move between the boxes and perform the calculation with the tab key.
- The result can be compared to the data below to assess whether the change in analyte
concentration is due to clearance alone, or whether other factors are involved.
- If several results are available during the fall in analyte concentration the half-life
calculated from each pair should be similar.
- Both results must be taken from the time when the analyte concentration is falling.
Falsely long half-livers can be seen if the first result is taken prior to the analyte
starting to fall or if the second result is taken after the fall in concentration is
completes.
- The data is not stored electronically. All transcriptions must be checked for errors.
Half-life Reference Data.
- AFP: 96-168 hours (4-7 days)
- ALP: 240 hours (10 days)
- CA 125: 144 hours (6 days)
- CK (skeletal): 15 - 18 hours
- CK-MB: 13 hours
- CRP: 19 hours
- GGT: 96 hours (4 days)
- Lacate: 4 hours (after siezures, physical activity)
- LDH: Between 10 (pure LD1) and 100 hours (pure LD5)
- Lipase: 7-13 hours
- Tri-iodothyronine: 36 hours
- Thyroxine: 169 hours (approx 1 week)
| (with thanks to M R Holland, Knowledge in Capsular Form) |
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