RESUMO
Objective To study the effect of self-modified Guth & Samaha's myosin-ATPase staining method on the classification of SD rat skeletal muscle fiber types.Methods 8 ?m-thick cryostat sections from rat chest muscles and biceps brachii muscles were transfected with cryostat.Myosin-ATPase staining was carried out according to the following procedure: ① Fixing sections for 5 min in fixative solution containing 40 g/L paraformaldehyde;② Rinsing slides in Tris-rinse solution and then preincubating them in alkaline preincubation solution for 15 min;③ Rinsing slides in Tris-rinse solution twice and then incubating them for 60 min in incubation solution;④ Washing slides for three times in 10 g/L CaCl2 and then placing them in 20 g/L CoCl2 for 3 min;⑤ Washing sides in distal water and then placing them in 10 g/L(NH4)2S for 3 min and;⑥ Washing slides in running tap water for 3 min,dehydrating in graded ethanol,clearing in xylene and mounting in neutral balsam.Results After being stained by modified myosin-ATPase staining method,both chest muscle and biceps brachii muscle samples from SD rats could be clearly identified as type Ⅰ fibers and type Ⅱfibers as the fibers of type Ⅰ were stained white while the fibers of type Ⅱ were stained brown.Conclusion Modified myosin-ATPase staining method is a simple and effective way for muscle fiber type classification and can be applied in skeletal muscle related study.