I am trying to knock down a gene in EBV-transformed lymphoblastoid B-cell lines (LCLs) using the CRISPR system. For this purpose, first I tried the lipofectamine mediated transfection of cells but the efficiency of lipofectamine with LCL was almost around 1%. Then I tried the nucleofection using the Lonza 2b system. Here the efficiency with the smaller positive control plasmid (eGFP, 4kb) was around 40-50% but with larger plasmids (px459) the efficiency is almost 1-5% and cell viability is also greatly reduced.

If anyone has tried larger plasmids nucleofection in LCL with high efficiency, please help me regarding this.

Thanking you in advance.