pHast Conjugates are one of our pHastest tools for quantitative testing of your primary material’s specificity, binding, and internalization, providing results in 1 day.
pHast Conjugates were built to answer that simple but critical question: did your targeting material actually internalize?
If internalization is a critical part of your research or development workflow, choosing the right assay format matters.
Using a pH-sensitive fluorescent reporter, pHast remains silent at neutral pH and activates only after internalization into acidic intracellular compartments.
The result is a direct, biologically relevant readout of true internalization with low background and a simpler workflow.
Researchers can use Fab-pHast to evaluate antibody fragments or Streptavidin-pHast to assess biotinylated targeting materials, including antibodies, peptides, and other compatible formats. The assay is also adaptable across multiple readout platforms, including microscopy, flow cytometry, and high-throughput screening.
Internalization data is only useful if you can trust what you’re seeing.
Because pHast Conjugates activate specifically in acidic intracellular compartments, they help distinguish internalized material from surface-bound signal and reduce the background that can complicate interpretation with traditional assays. The result is a clearer, more biologically relevant readout of internalization with less ambiguity and less assay complexity.
All of our pHast Conjugates are available with these fluorescent dyes and as a multi-color kit with all four colors in one in one bundle.
- The pHast BLUE has an excitation wavelength of 362 nm with an emission maxima at 452 nm. (PH-B)
- The pHast GREEN version has an excitation wavelength of 453 nm with an emission maxima at 522 nm. (PH-G)
- The pHast RED has an excitation wavelength of 532 nm with an emission maxima at 560 nm. (PH-R)
- The pHast FAR-RED has an excitation wavelength of 643 nm with an emission maxima at 660 nm. (PH-F)
- The pHast Multi Color Kit has all four colors in one bundle. (PH-K)
| Target | Recommended Products made with whole IgG | made with monovalent (Fab) | made with monovalent Fc region (FabFc) |
|---|---|---|---|
| biotinylated materials | Streptavidin-pHast (PH-03) made with Streptavidin and a pH-dependent fluorescent reporter | ||
| alpaca/llama IgG (VHH domain) | Alpaca-pHast (VHH) (PH-05) | Fab-pHast Alpaca (VHH) (PH-21) | |
| alpaca/llama IgG | Alpaca-pHast (IgG) (PH-20) | ||
| chicken IgY | Chick-pHast (PH-06) | ||
| goat IgG | Goat-pHast (PH-07) | ||
| guinea pig IgG | gPIG-pHast (PH-08) | ||
| human IgG | Hum-pHast (PH-09) | Fab-pHast human (PH-01) | FabFc-pHast human (PH-10) |
| human IgM | Hug-M-pHast (PH-11) | FabFc-pHast Hug-M (PH-04) | |
| mouse IgG | Mab-pHast (PH-12) | Fab-pHast mouse (PH-02) | FabFc-pHast mouse (PH-13) |
| mouse IgM | Anti-M-pHast (PH-14) | ||
| rabbit IgG | Rab-pHast (PH-15) | Fab-pHast rabbit (PH-16) | |
| rat IgG | Rat-pHast (PH-17) | Fab-pHast rat (PH-18) | FabFc-pHast rat (PH-19) |
 made with bivalent antibodies that recognize the whole IgG |  made with monovalent (Fab) antibodies that recognize the whole IgG, without bivalent capping |  made with monovalent (Fab) antibodies that recognize Fc region only | |