A new stereological method is proposed which combines vertical slice projections with the fractionator to
estimate the total capillary length in a skeletal muscle. The method was demonstrated on the soleus muscle
of a Wistar rat. The implementation required capillary highlighting, tissue sampling, and data acquisition in
the form of intersection counts between capillary projections and cycloid test lines. The capillaries were
demonstrated using vascular perfusion (with gelatine) of the hind leg of the rat. The sampling procedure
followed the fractionator design, namely a multistage systematic sampling design with a known sampling
fraction at each stage. To make the design unbiased, vertical slices were used; for efficiency, the vertical axis
was chosen parallel to the main axis of the muscle. As prescribed to avoid bias, the cycloid test lines were
superimposed on the slice projections, viewed under the light microscope, with their minor axes normal to
the vertical axis. The estimation precision was compared for different sampling and subsampling fractions.
The proposed method was globally highly efficient, unbiased, and easy to implement.