Table 2. Table shows the initial results of quantification of ROS in rat myocardial tissue samples (first column) and the results of a repeated series of measurements after storage in −80°C during six month (second column).

Biopsy#	Initial measurements[ROS] (µM)	Measurements after storage at−80°C during six months [ROS] (µM)	Difference Δ(µM)
1	58	54	−4
2	57	56	−1
3	67	71	4
4	102	111	9
5	24	24	0
6	69	73	4
7	77	73	−4
8	56	51	−5
9	64	62	−2
10	59	60	1
11	83	82	−1
12	47	45	−2
13	33	36	3
14	34	34	0
15	97	98	1
16	64	60	−4

Third column show the difference between the two measurement sessions. (Estimated uncertainty ±10 µM (k = 1)).