Table 4.

Inactivation of MCT1 Ag by formalin fixation ^a

		% Loss of fluorescence intensity
Time in formaldehyde (3.7%) at 4C	Trials	Mean	SD	SE
10 min	4	3.5	12.5	6.2
2 hr	3	49.7	9.1	5.2
3 hr	3	72.0	17.8	10.3
24 hr	3	82.0	10.6	6.1

^aLoss of fluorescence intensity was measured by automated exposure time required to produce the same photographic image of the same field of view as an unfixed frozen section, after various immersion times of sequential 6-μm frozen human muscle sections in 10% formalin (3.7% formaldehyde) in PBS at 4C Analysis of variance (1-way) yielded an F-ratio of 26.38 and p<0.01%. Post hoc testing gave significant linear trend increase at the 0.01% p level. The Tukey test showed that the 10-min mean differed at the 1% level or beyond from all later means, and the Newman-Keuls test added a significant difference between the 2-hr and 24-hr means at p<5%.