Opteia human ifn γ elisa kit 2

The cytotoxic activity of human NK cells was measured using K562 as target cells in vitro. In some experiments, human NK cells were stimulated with 2 ng/ml IL-2, 2 ng/ml IL-12, 2 ng/ml IL-15 (Miltenyi Biotec), or 2 ng/mL IL-18 (Medical & Biology Laboratories, Nagoya, Japan), either alone or in combination for 48 h before use. These cells were subsequently incubated with K562 for 4 h. The effector/target ratio was 10: 1. The release of lactate dehydrogenase (LDH) into the culture supernatant was measured using a Cytotox96 non-radioactive cytotoxicity assay kit (Promega, Madison, WI, USA). We used OptEIA Human IFN-γ ELISA Kit II (BD Biosciences) for measuring the amount of human IFN-γ in the culture supernatants.

PBMC were stimulated with 10 μg PPD in 24-well tissue culture plates for 6 h. Supernatants were collected by centrifugation and stored frozen at −80°C. Levels of IFN-γ in culture supernatants were assayed using commercial ELISA kits [OptEIA™ Human IFN-γ ELISA kit II (BD Biosciences, San Jose, CA, United States)], according to manufacturer's instructions.