While CRISPR-Cas9 has revolutionized gene editing, the need for selection remains. When inserting a large DNA sequence via Homology Directed Repair (HDR), scientists often include a PGK-Neo cassette within the donor template. This ensures that the resulting colonies are not just indels (random edits) but precise insertions of the new genetic material.
: This gene encodes an enzyme that detoxifies the antibiotic G418 (Geneticin). When integrated into a cell's genome, it allows that cell to survive and replicate in medium containing G418, while non-modified cells perish. pgk-neo
To understand why this cassette is so powerful, it is necessary to examine its two core components individually. While CRISPR-Cas9 has revolutionized gene editing, the need
The PGK promoter is derived from a housekeeping gene, meaning it works reliably in almost any mammalian cell line, from stem cells to primary fibroblasts. Some stronger promoters, like CMV, can be silenced over time by the cell’s epigenetic defense mechanisms or may not work well in certain cell types. PGK offers a "slow and steady" reliability that is perfect for selection markers. : This gene encodes an enzyme that detoxifies
: Often the bovine growth hormone (bGH) or SV40 poly(A) signal, which ensures proper termination and stability of the mRNA transcript. Primary Applications