To determine the correct sample type and volume for cytokine testing services, consider the assay platform, format, sensitivity, cytokine expression levels, and stability in different matrices. Some common sample types for cytokine testing services are plasma, serum, cell culture supernatants, PBMC, urine, tissue lysates, cell lysates, and CSF. The sample volume depends on the number of cytokines to be measured, the assay sensitivity, and the dilution factor. Generally, the sample volume ranges from 25 to 100 μL per well.