Phenol Red (PSP)

Phenol red is a pH indicator that is frequently used in cell biology laboratories. Phenolsulfonphthalein test. was used to estimate the overall blood flow through the kidney and is now obsolete. The test is based on the fact that phenol red is excreted almost entirely in the urine. Phenol red solution is administered intravenously, the urine produced is collected. By measuring the amount of phenol red excreted colorimetrically, kidney function can be determined. Previously, human eggs had only been produced in vitro from totipotent, blastomeric embryonic stem cells. One of the significant aspects of this experiment is that it demonstrated viable human egg cells can easily be produced from an adult cell that already has some degree of specialization. Furthermore, it lessens the implications associated with the fact that women are born with all of the egg cells they will ever have throughout their lives.