Probenecid *Cell culture tested* *CAS 57-66-9*

Probenecid is an inhibitor of organic-anion transporters located in cell membranes. These transporters often extrude fluorescent indicators from cells, and therefore contribute to poor dye retention. This phenomenon usually causes high background in the assays that require the good retention of the dye indicators inside cells. The use of probenecid to inhibit the transporter activity, and thus to reduce leakage of the intracellular dye indicators is a common method for reducing fluorescence background of calcium assays. Each vial is dissovled in 0.3 mL of 1 M NaOH, and then diluted into 100 mL buffer to make 2.5 mM final concentration of probenecid for your assays.