I was wondering what is the limit of detection for Human IFN-g/IL-4 FluoroSpot Flex Kit (Catalog X-01A16B-10)? I tried to look for this information in the Datasheet but without success. Could someone help me with this?
Thanks in advance.
Maria
Forums
Limit of detection for Human IFN-g/IL-4 FluoroSpot Flex Kit (Catalog X-01A16B-10)
- GMGuest Maria2024-10-23T19:56:23Z
- CChristian@mabtech.com2024-10-24T09:06:18ZAdmin
Dear Maria, welcome to the forum!
ELISpot and FluoroSpot are known as one of the most sensitive cellular assay available. However, defining an exact level for the limit of detection is currently not possible. The reason for this is that you would have to be able to engineer and artificial cell secreting a known quantity of cytokine. No such technology currently exist.
Instead you are left to do comparisons with ELISA like techniques where sensitivity of ELISpot/FluoroSpot often comes out much much higher (10-1000x). At the same time, these two techniques don't exactly measure the same thing. ELISA measurements of cytokines is based on free molecules found in cell supernatant. By contrast, ELISpot is the captured cytokines right after they are released by the activated cell. Due to this immediate capture, ELISpot/FluoroSpot is not affected by soluble receptors and protease activity, which can affect ELISA. IL-4 is notoriously difficult to detect in ELISA, but easily found in ELISpot just for this exact reason.
In this paper they have done a comparison between ELISpot and ELISA where they titrate an NK cell line and assess Perforin secretion using the same antibody pairs:
https://pubmed.ncbi.nlm.nih.gov/16647080/