From Protein Detection to Drug Discovery: Key Applications of HiBiT Tagging in CRISPR Knock-In Cell Models

Updated July 23, 2026.

Key Takeaways

• HiBiT is an 11-amino-acid peptide tag that enables sensitive luminescent detection of endogenous proteins.
• Compared with antibody-based tags such as FLAG and HA, HiBiT provides quantitative measurement without antibody validation.
• HiBiT tagging is compatible with CRISPR knock-in workflows for generating functional cell models.
• Applications include protein degradation studies, target engagement assays, pathway analysis, and drug discovery.

Simplicity, Sensitivity, and Speed in One Tag

Measuring endogenous protein levels is essential for understanding biological pathways, validating drug targets, and studying protein stability. However, traditional approaches such as Western blotting and antibody-based detection often require extensive optimization, provide limited quantitative information, and may not be compatible with live-cell workflows.

HiBiT tagging provides an alternative approach by enabling sensitive, quantitative measurement of endogenous proteins through a small peptide tag and luminescence-based detection—helping researchers study protein expression, degradation, and regulation while preserving native biology.

From drug discovery to pathway validation, this approach supports applications where accurate measurement of endogenous protein levels is critical. In contrast to larger tags or antibody-dependent methods, HiBiT offers a streamlined workflow for researchers studying protein function in engineered cell models.

What is HiBiT, and Why Should You Care?

HiBiT is an 11-amino-acid peptide tag that, when combined with its complementary partner LgBiT (provided in Promega’s detection reagents), reconstitutes an active luciferase enzyme. The result? A bright, quantitative luminescent signal directly proportional to the amount of tagged protein in the sample.

It’s that simple—and that powerful.

How HiBiT Outperforms Conventional Tags

With HiBiT, you eliminate the headaches of antibody validation, signal variability, and overexpression artifacts. Whether you’re working with engineered cell lines or transgenes, HiBiT gives you functional fidelity—you tag your protein without compromising its behavior.

Real-World Example: Using HiBiT to Uncover the CK2–CARD9 Axis in Innate Immunity

In a recent study out of Bristol Myers Squibb, researchers sought to understand the upstream regulation of CARD9—a critical adaptor protein in antifungal innate immune signaling. While CARD9’s role in activating inflammatory pathways was well established, the molecular mechanisms controlling its stability and degradation remained poorly defined.

To solve this, the team used EditCo to generate a CRISPR knock-in THP-1 cell line with endogenous CARD9 tagged using HiBiT. This enabled real-time, quantitative measurement of native CARD9 protein levels via luminescence—without the need for antibodies or overexpression artifacts.

With this platform in place, the team performed a targeted CRISPR knockout screen of individual casein kinase 2 (CK2) isoforms and subunits. The results were striking: loss of CK2α (CSNK2A1) and CK2α′ (CSNK2A2) significantly stabilized CARD9 protein levels, while other CK2 components had minimal or no effect. This revealed, for the first time, that phosphorylation by CK2α/α′ drives CARD9 degradation—establishing a direct link between kinase activity and CARD9 protein turnover.

HiBiT’s high sensitivity and compatibility with arrayed genetic perturbation enabled rapid, mechanistic profiling of immune signaling pathways that would have been far more laborious using traditional Western blot or antibody-based approaches.

EditCo Highlight: Endogenous HiBiT tagging revealed CK2α/α′ as critical regulators of CARD9 stability, unlocking new insights into immune signaling and enabling translational exploration of this pathway for autoimmune disease.

Use Cases Where HiBiT Shines

Whether you’re working in drug development or basic discovery, HiBiT opens up new possibilities:

• Target Engagement Assays
  Quantify drug-induced degradation or stabilization of your target protein in live cells.
• Mechanism-of-Action Studies
  Monitor how your perturbation affects protein expression, turnover, or cellular localization.
• Pathway Mapping
  Track protein changes in real time across signaling cascades—no blotting required.
• Gene Regulation Screens
  Quantify transcriptional and post-translational effects with luciferase-like sensitivity.
• Cell Therapy Research
  Monitor persistence or differentiation markers with minimal cellular perturbation.

Why Outsource Your HiBiT Knock-ins?

HiBiT sounds great—until you realize your team doesn’t have the capacity to make CRISPR knock-in lines, especially if you’re working with hard-to-edit cell types or tight timelines.

That’s where EditCo comes in.

Through our partnership with Promega, EditCo now offers custom HiBiT-tagged cell lines—with:

• CRISPR/RNP precision (no plasmids)
• NGS-validated integration with optional functionality testing
• Licensing coverage handled on your behalf
• Short delivery timelines aligned with drug discovery sprints.

Whether you’re tagging an endogenous gene or introducing a tagged transgene, we handle the heavy lifting so you can stay focused on the science.

Frequently Asked Questions

Q: We already use FLAG or HA. Why switch?

HiBiT offers true quantitation, live-cell compatibility, and removes the need for validated antibodies. It’s not just a convenience—it’s a fundamentally more scalable, reproducible system.

Q: Can I use HiBiT in primary or iPS cells?

Yes. We’ve successfully integrated HiBiT into primary fibroblasts, neural progenitors, iPSCs, and other challenging models. Ask us about your specific cell type.

Q: What about detection? Is the assay complicated?

Detection is easy. Promega’s detection kits supply the LgBiT protein and substrate. Add reagent, incubate for 10 minutes, and read luminescence. That’s it.

Q: We already did a HiBiT knock-in before—do we need to worry about licensing now?

With our Promega licensing agreement, EditCo now covers your use of HiBiT in our custom cell lines—removing the burden of compliance and making future projects seamless.

Ready for custom HiBiT knock-ins?

Request a quote today!