Lactate dehydrogenase assay ldh assay

Lactate dehydrogenase assay (LDH assay) (Abcam, UK) was used to detected the specific killing activity of CAR-T cells toward target cells. The manufacturer’s instructions were followed. Target cells were co-cultured with CAR-T cells at various E:T ratios for 24 h, supernatants were collected and incubated with Cytotox 96 regent for 30 min. Finally, stop solution were added to each well followed by quantification of absorbance at 490 nm.

The cytotoxicity of CAR-T cells and CAR-Exos toward target cells (MSLN-LLC) was assessed using the Lactate Dehydrogenase Assay (LDH assay) (Abcam, UK). Briefly, 1 × 10⁴ MSLN-LLC cells were seeded per well in 96-well plates. Following overnight incubation, CAR-T cells were incubated with MSLN-LLC cells at different E:T ratios. For CAR-Exos, different concentrations of exosomes were mixed with MSLN-LLC cells. After 24 h co-culture, the cell supernatant was measured for LDH reactivity by enzymatic reaction and measured with a microplate reader. Cell death was measured as a percentage of total LDH release, according to the manufacturer’s protocol.