KRIBIOLISA Runimotamab ELISA includes features like:
– Ready to use protocol with break-apart wells for ease of use
– Standardisation and High Reproducibility
– Lot to Lot Consistency
– Accuracy and Precision
Validated against seven points for a “GOLD RING” Standard Quality ELISA – the benchmark sign for Krishgen Quality. KRIBIOLISA ELISA kit is used for assessing the specific biomarker in samples analytes which may be human serum, plasma, biological fluids and cell culture supernatant. The kit uses indirect sandwich assay with double antibodies / recombinant proteins – capture and detection to ensure a high degree of sensitivity and specificity in the estimation of the analyte. Extensive validation has been done on these kits. Please ask for our validation guide if not availableon our product page. Incase you wish us to customize the kit, connect with us at sales1@krishgen.com
Frequently Asked Questions
1. Does the assay quantify total runimotamab or only free (target-unbound) runimotamab?
Since the capture is a HER2 protein, It will measure free runimotamab, or more precisely drug with an unoccupied HER2-binding site, and for signal, an unoccupied CD3 arm as well.”
2. If anti-idiotype antibodies are used in the assay, are they blocking or non-blocking with respect to HER2 binding?
There is no anti-idiotypic antibody used in this assay but two proteins as the capture and detection since Runimotamab is a bispecific. As indicated above the capture binds to HER2.
Note the assay will not work in the tissue homogenate sample. In HER2-high tissue, receptor is in vast molar excess over drug. The moment you lyse, membrane HER2 that was bound at the cell surface is released into solution still bound to drug, and free HER2 floods the lysate. Essentially all drug in that sample will be HER2-occupied, and any free drug you add or release will be re-captured within the homogenate. So: A HER2-capture free assay reads near zero in tissue. Not useful.
What we would recommend is a custom service assay development in the following lines –
Plasma may genuinely want both. Free (target-available) drug for PK and PD correlation, total for mass balance and for understanding how much shed HER2 ECD is sequestering. If the customer is comparing plasma exposure to tissue exposure, both numbers need to be on the same footing, which argues for total in both matrices as the primary assay, with free in plasma as a secondary.
3. Is the assay suitable for quantifying runimotamab in human HER2-high expressing tumor tissue homogenates?
Our primary interest is understanding whether HER2-bound runimotamab can be accurately measured by this assay.
So the recommended primary format is a total-drug assay that is blind to HER2 occupancy:
Capture on a CD3ε/δ-Fc heterodimer, detect with anti-human Fc, HRP-conjugated. HER2 bound to the drug’s other arm doesn’t interfere with either step. Pair this with acid dissociation pretreatment — brief incubation at low pH to strip HER2 and any ADA, then neutralize directly into the capture plate. The acid step is what converts this from “total if nothing is bound” to genuinely total.
For tissue specifically, add a scavenging step: after neutralization, the released HER2 will try to re-bind. Including excess trastuzumab (or a domain IV blocker) in the neutralization buffer occupies free HER2 without touching your capture or detection chemistry. Validate that it doesn’t cross-react with your anti-ID.
Anti-human Fc detection works cleanly in tissue homogenate but fails in human plasma because of endogenous IgG. For plasma you’d add the acid-dissociation step.
