By Iveta Bottova, PhD
Dendritic cells (DC) population is a key functional constituent of cell based immunotherapy drugs. The correct cell count and adequate viability of DC are one of the quality control criteria for the final product release. Number of viable DC is historically determined by microscopy using manual counting method – Bürker chamber and trypan blue dye for dead cell exclusion. The manual method can have significant variability between cell counts determined by different people performing the manual counting, which may contribute to an unstable manufacturing process. The manual method is also time consuming for the operator. An automated cell counting process would remove the variability between operators2 and could free up the operator for other tasks. The Vi-CELL XR (Vi-CELL) is an automated cell counting and viability analyzer that uses the trypan blue dye exclusion method. The Vi-CELL was evaluated as a suitable method for Quality Control of DC count and viability for a dendritic cell-based drug. The test for Vi-CELL counting accuracy was performed on concentration control beads of known concentration three times under the same operating conditions. Diameter and circularity of DC and lymphocyte was determined by NIKONTM Eclipse microscope to set up the correct recognition of DC to exclude lymphocytes for Vi-CELL counting. The size range for DC was established so lymphocytes were excluded and number of total DC, number of viable DC and DC viability were analyzed and compared to Bürker chamber counting. There was no significant difference between DC count obtained by Vi-CELL and by Bürker chamber. Vi-CELL automated cell counter was established as a method which is accurate and suitable for DC counting.