All of this is for reverse transfections (split cells and combine with siRNA/lipid mixture)
These were optimized to obtain highest transfection efficiencies with lowest toxicity
You can use the Qiagen Cell death control siRNA to ensure you are doing it correctly. This mixture of siRNAs should kill all of the cells in about 48 hours.
Knockdown is usually best at 72 hours post transfection. However, often 48 hours is enough.
Be sure to split cells on days after transfection as needed to prevent them from becoming confluent.