phenolsulfonphthalein

phe·nol·sul·fon·phthal·e·in (PSP),

(fē'nol-sŭl'fōn-thal'ē-in, -thal'ēn),

An indicator in tissue culture media (yellow at pH 6.8, red at pH 8.4); occurs as a bright to dark red crystalline powder; in the past given by parenteral injection as a test for renal function.

Synonym(s): phenol red

phenolsulfonphthalein

(fen?ol-sul?fon-thal'e-in, -thal'en?),

P.S.P.

A bright red organic chemical C₁₉H₁₄O₅S used diagnostically in studies of kidney function, bladder emptying, and, after intra-amniotic injection, in invasive tests for premature rupture of membranes.

CAS # 143-74-8

Synonym: phenol red