Endogenously expressed PRG3 is found in the plasma membrane of primary hippocampal neurons after DIV 1. (A) Confocal images of a representative primary hippocampal neuron fixed after DIV 1. Low (top row) and high (bottom row) magnification of this neuron showed that PRG3 (anti-PRG3 296, green) is not co-localized with α-tubulin (anti-α-tubulin, red) and is likely located in the plasma membrane. (B) Confocal images of a primary hippocampal neuron stained with anti-PRG3 296 (green) and anti-β-actin (red) after DIV 1. As in (A), PRG3 is located in the plasma membrane, but is only present in actin-rich regions and growth cones at low levels. Overview (top row), scale bar: 10 μm, higher magnification (bottom row), scale bar: 5 μm.