Transmission electron micrograph of a highly magnified and cropped image of a capillary in a mouse cardiac muscle. The capillary is used mainly for the transport of nutrients and oxygen through the elaborate network of branches. Made up of endothelial cells the capillary has the ability to constrict or dilate when signaled by the body. Red blood cells average about 7.7 um in diameter and seen here as a darkly colored region in which its’ sole function is to deliver oxygen throughout the tissues of the body.
Primary fixation included: 2.5 % glutaraldehyde, 2% formaldehyde in 0.1 M Na-phosphate buffer, pH 7.4. Post-fixed in 2% OSO4 in 0.1 M Na-phosphate buffer, pH 7.4. Stained en bloc in 1% uranyl acetate. The tissue was then dehydrated in a graded series of ethanol and infiltrated with Spurr’s resin. Thin sections of 70 nm were trimmed using a diamond knife and post-stained in uranyl acetate and lead citrate. This micrograph image was taken using a Phillips CM 100 transmission electron microscope at an accelerating voltage of 80kV.