To improve the efficacy of the dendritic cell vaccine Alv B DC from Alv B, the PD-L1 expression in cancer cells was attempted to be reduced through a transfection with a custom designed siRNA. Before transfecting the dendritic cells, the siRNA functionality had to be tested through flow cytometry, that resulted in negative results and therefore led to a RT-qPCR protocol that indicated that the siRNA was functional. Protocols for the two methods were developed and a cell line expressing PD-L1 was set up as a tool for testing. The final goal of testing the effects in Alv B DC was never performed due compromising time but the positive result from the PCR provides a promising start to further testing.