The use of this kit on formaldehyde or formalin fixed cells has not been assessed in our lab, and our literature survey has not provided a recommended protocol reference.
It's important to note that fixing cells with a crosslinker such as formalin or formaldehyde could potentially impact the results of this assay. The harsh conditions of crosslinking may lead to cell membrane damage and increased cell death. As this has not been tested in our lab, we highly recommend conducting a pilot experiment to confirm compatibility.