How does a chromium release assay work?

The chromium-release assay developed in 1968 is still the most commonly used method to measure cytotoxicity by T cells and by natural killer cells. Target cells are loaded in vitro with radioactive chromium and lysis is determined by measuring chromium in the supernatant released by dying cells.

How do you calculate specific lysis?

The percentage of specific lysis for each well was calculated as follows: % specific lysis = 100 – ((CFSE low/CFSE high) in the presence of effector cells / mean of the three wells containing target cells alone in the absence of effector cells) x100.

What are cytotoxicity assays?

Cytotoxicity assays measure the ability of cytotoxic compounds to cause cell damage or cell death. Cytotoxicity assays are widely used in fundamental research and drug discovery to screen libraries for toxic compounds.

What is Chromium-51 used for?

Chromium Cr-51 is an isotope of chromium that is observationally stable. When intravenously administered, it is used as a diagnostic radiopharmaceutical agent to determine the red blood cell volume or mass, study the red blood cell survival time and evaluate blood loss 1.

How do you measure cytotoxicity of T cells?

CD8+ T cell cytotoxicity can be measured using multiple methods including measuring IFN╬│ production by ELISPOT or measuring intracellular cytokines or cytotoxic granules by flow cytometry.

What is toxic to cells?

Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (Bitis arietans) or brown recluse spider (Loxosceles reclusa).

How is a cytotoxicity assay done?

A frequent use of cells in culture is for a commonly used cytotoxicity assay where cells are exposed to a test compound and after some period of incubation, a marker is measured to reflect the number of viable cells present compared to positive (toxin) and negative (vehicle) control treatments.

How do you perform a LDH assay?

To perform the assay, an aliquot of the cell culture medium is transferred to a new plate and the reaction mixture is added. After a 30-minute incubation, the reaction is stopped by adding Stop Solution and absorbance is measured using a microplate reader.

Why is LDH release a good measure for cytotoxicity?

This LDH cytotoxicity assay is capable of detecting low level damage to cell membrane which cannot detected using other methods. And since it does not damage healthy cells, the LDH cytotoxicity assay can be performed directly in the cell culture wells containing a mixed population of viable and damaged cells.

What type of radiation does chromium 51 emit?

gamma rays
Chromium-51 is a commonly used radionuclide with a half-life of 27.7 days, emitting gamma rays with a maximum energy of 0.320 MeV (Million Electron Volts).