Genetic modifications using CRISPR-Cas9 have revolutionized cancer research and other preclinical studies. Exceptionally, these efficient tools are inadequate in a few disease models and cell lines due to the aberrant differentiation states and the accumulation of excessive somatic mutations that compromise the robustness of viral gene delivery and stable transduction. A couple of B lymphoma cell lines fall into this category where lentiviral transfection becomes inefficient and exhibits variable efficiency. Additionally, lentiviral delivery requires high biosafety levels. To address this challenge, we have developed a two-step strategy that supports CRISPR-Cas9 through lentivirus and murine ecotropic γ-retrovirus. By engineering B lymphoma cell lines to express Cas9 and mCat1, a specific receptor for ecotropic retroviruses, we enable efficient and safe gene editing through ecotropic γ-retrovirus. We demonstrate the efficacy of this method by generating IgM-deficient B lymphoma cell lines. This innovative approach simplifies protocols, enhances accessibility, and paves the way for standardized gene manipulation of B cell lymphoma models for molecular cell biology research.