Multiple biopsy samples from each patient were stored in paraformaldehyde and embedded en bloc in paraffin.
All samples were, immediately after collection, embedded en bloc in Tissue Tec OCT (Miles, Elkhart, IN, USA) and subsequently snap frozen.
9 10 Specimens were directly embedded en bloc in TissueTek OCT (Miles Diagnostics, Elkhart, Indiana, USA) and subsequently snap-frozen in liquid nitrogen.
To determine the distribution of B cells and FDCs in lymphocyte aggregates, we evaluated two separate tissue sections (each section representing one level of the six biopsy samples that were embedded en bloc), located 50 μm apart, which were stained with the anti-CD22, anti-CD23 and anti-CD21L antibodies.
From paraffin-embedded blocs 2 consecutive 12 μm thick slides were cut and stained with Luxol-van Gieson staining for the visualization of myelin as well as haematoxylin-eosin and haematoxylin-eosin for cellular and structural analysis [ 20].
The resected specimens were fixed in 10% formaldehyde, en bloc embedded in paraffin and sectioned into 5- μm slices which were stained with haematoxylin and eosin.
They were post-fixed with 1% OsO4 in 1.5% K4Fe CN 6 and 0.1 M sodium cacodylate, en bloc stained with 0.5% uranyl magnesium acetate, dehydrated and embedded in Embed 812.
The pellet was stained en bloc with 2% aqueous uranyl acetate followed by ethanol dehydration and embedded in EMbed (EMS).
Cells were stained en bloc with 2% uranyl acetate in 25% acetone, dehydrated in graded acetone concentrations, and embedded in EMbed-812 (Electron Microscopy Sciences, Fort Washington, PA, USA).
Fixed samples were en bloc stained with 2% uranyl acetate, dehydrated through series of ethanol and propylene oxide, and embedded in EMbed-812 resin.
Sections were en bloc stained with 2% uranyl acetate in 25% acetone, dehydrated in graded acetone concentrations, and embedded in EMbed-812 (Electron Microscopy Sciences, Fort Washington, PA, USA).
