Days of storage (dried serum)

Serum GGT Levels (U/L)

Mean (SD) (N = 12)*

Day 0 Direct

346.2 (436.16)

Day 0 dried serum

339.35 (440.53)

Week 1

322.13 (409.08)

Week 2

328.22 (402.12)

Week 3

325.07 (406.48)

Week 4

312.67 (393.19)