Figure 3.

Initial evaluation of non-CD34 blood vessel markers. We tested a variety of potential blood vessel markers for use in mouse brain tissue. (a) CD31 stained blood vessels lightly, but also showed some non-vascular cell staining. (b) Analysis by the microvessel algorithm identified blood vessels, but also cell staining (blue arrows). There were many vessels left unidentified (red arrow). (c) Collagen IV stained blood vessels lightly, with very low background. (d) Given the light staining, the microvessel algorithm clearly missed some visible blood vessels (red arrows). (e) The DP71 stained slide had moderately high background staining, but showed both blood vessel and cell body staining. (f) The microvessel algorithm readily detected blood vessels, but also misidentified cell staining as blood vessels (blue arrows). (g) The von Willebrand Factor (VWF) stained slide had very high background. (h) The background was so high that the algorithm could not identify any blood vessels. The entirety of the displayed region of interest was excluded from analysis (yellow shading). The number of vessels identified by the algorithm (i), as well as the vessel density (j) varies significantly for each antibody. CD31 and DP71 identified the most vessels, possibly due to the non-vessel cell staining. Red boxes indicate the region of interest analyzed by the microvessel algorithm, shown in the second panel for each antibody.