Description
Inosine-5'-Monophosphate Dehydrogenase (IMPDH) Activity Assay Kit
The Assay Genie Inosine-5'-Monophosphate Dehydrogenase (IMPDH) Activity Assay Kit measures IMPDH (EC 1.1.1.205) activity in cell and tissue lysates. IMPDH catalyses the NAD+-dependent oxidation of IMP to xanthosine monophosphate (XMP), the rate-limiting step of de novo guanine nucleotide synthesis. Its isoforms IMPDH1 and IMPDH2 are targets of immunosuppressive, antiviral and anticancer drugs such as mycophenolic acid and ribavirin.
NADH produced by IMPDH reduces the tetrazolium dye INT to a coloured formazan read at 492 nm in a 96-well plate. With direct calculation in IU/L and a per-sample control, the kit is suited to both basic purine metabolism research and IMPDH drug screening.
| Product Name: | Inosine-5'-Monophosphate Dehydrogenase Assay Kit |
| SKU: | BR00010 |
| Kit Size: | 100 wells |
| Detection Method: | Colorimetric (INT → formazan, OD 492 nm) |
| Sample Types: | Cell and tissue lysates; IMPDH drug screening |
| Recommended Protein: | 1–3 mg/ml |
| Incubation Time: | 60 or 90 min at 37 °C |
| Units: | IU/L (µmol/L/min); normalise to protein or GAPDH |
| Equipment Required: | Microplate reader (492 nm) |
| Storage: | -80 °C (see component storage) |
| Intended Use: | For research use only (RUO). Not for diagnostic procedures. |
- Measures the rate-limiting enzyme of guanine nucleotide synthesis
- Suitable for IMPDH inhibitor and drug screening
- Direct activity calculation in IU/L, no standard curve required
- Per-sample no-substrate control
- Includes 10x Sample Buffer for lysate preparation
- IMPDH oxidises IMP to XMP, reducing NAD+ to NADH.
- NADH drives the reduction of INT to a coloured formazan. Formazan has an absorbance maximum at 492 nm (ε = 18 mM-1cm-1), so activity is calculated directly in IU/L (µmol/L/min) without a standard curve.
- Activity is calculated from ΔOD (reaction − control): IU/L = ΔOD × 8.1 (60 min) or × 5.4 (90 min).
- Cells: ≥105 freeze-thawed cells in 50–100 µl ice-cold 1x Sample Buffer.
- Tissue: ~5 mg tissue per 500 µl ice-cold 1x Sample Buffer.
- Centrifuge at ~14,000 rpm for 5 min at 4 °C; adjust protein to 1–3 mg/ml.
| Component | Size | Storage |
| IMPDH Assay Solution | 5 ml | -80 °C, protect from light |
| 50x IMPDH Substrate | 0.1 ml | -80 °C |
| 10x Sample Buffer | 25 ml | 4 °C |
- Purine and guanine nucleotide metabolism
- Immunology and lymphocyte proliferation (mycophenolic acid)
- Antiviral research (ribavirin) and cancer metabolism
- IMPDH inhibitor and drug screening
Can I use the IMPDH kit for drug screening?
Yes. The kit is suitable for measuring IMPDH activity in lysates and for screening IMPDH inhibitors.
What protein concentration is recommended?
1–3 mg/ml lysate protein, with normalisation across samples recommended.
How is IMPDH activity calculated?
ΔOD at 492 nm (reaction − control) × 8.1 for 60 min or × 5.4 for 90 min, giving IU/L.
