Four laboratories participated. Two protocols gave a good staining, two gave an acceptable staining. The difference was considered mainly due to differences in epitope retrieval methods.

Good protocol 1

Lab. A. Normal liver stained for CD34 using a good protocol (1). Endothelial cells are intensely stained in the portal tract and sinusoids in zone 1.

Lab B. Normal liver (same field as in (A)) stained for CD34 using an acceptable protocol. The staining is, however, somewhat weaker than in A.

Last update: 20-08-03