Table 1.

The cyclosporine A and tacrolimus levels of the samples stored under different storage conditions.

Sample	Cyclosporine A (mean ± SD) (ng/mL) (n = 15)	Percent change (%)	Tacrolimus (mean ± SD) (ng/mL) (n = 15)	Percent change (%)
Immediately analyzed (baseline value)	417.66 ± 449.02a,b,c		7.69 ± 2.62a
Kept 24 hours at room temperature	377.09 ± 398.69	−9.71	5.16 ± 1.84	−32.89
Kept 24 hours at +4°C	499.02 ± 520.05	19.47	6.63 ± 2.29	−13.78
Kept 48 hours at +4°C	481.90 ± 485.28	15.38	6.89 ± 2.95	−10.4
Stored at −20°C for one month	401.67 ± 421.58	−3.82	7.62 ± 4.45	−0.91

^a P = 0.005 for tacrolimus and P = 0.011 for cyclosporine A when compared with the samples kept 24 hours at room temperature.

^b P = 0.003 when compared with samples kept 24 hours at +4°C.

^c P = 0.003 when compared with samples kept 48 hours at +4°C.