A transparent loading apparatus (also referred to herein as a “loader”) may partially or entirely comprise transparent material that allows light to pass through the loader and provides the viewer (whether manual or automated) a view of a radioactive seed, a seed carrier, a loading needle, etc. within the loader. In some embodiments, carrier material (e.g., collagen and/or other biocompatible material) and radioactive seeds (e.g., including a metal shielding and radioactive isotope) may transmit light to different degrees. For example, certain carriers, such as collagen carriers, may be translucent, while seeds may be opaque (or mostly opaque) to light. The systems discussed herein allow a viewer to detect location of a seed within a loader, and even within a carrier, because of these different light transmissivity characteristics.