In the realm of forensic science, the presumptive identification of blood at crime scenes is a critical first step. The Kastle-Meyer test, a long-standing method, utilizes phenolphthalein in a modified form known as phenolphthalin. This test leverages the catalytic activity of hemoglobin present in blood. When a suspect sample is treated with phenolphthalin and hydrogen peroxide, the presence of hemoglobin causes the rapid formation of a pink color, indicating a potential bloodstain. This color change is a direct consequence of phenolphthalein's chemical properties reacting to the presence of hemoglobin's oxidizing power.

While not a definitive test for human blood, the Kastle-Meyer test, employing phenolphthalein, serves as an invaluable preliminary screening tool. Its relative simplicity and the distinctive color reaction make it a staple in forensic kits. For forensic professionals, access to pure and reliable phenolphthalein is paramount for accurate results. NINGBO INNO PHARMCHEM CO.,LTD. is a trusted supplier, providing the necessary quality of phenolphthalein for critical forensic applications. Ensuring the availability and competitive price of phenolphthalein is vital for crime scene investigation units globally. Purchasing phenolphthalein from established suppliers guarantees its efficacy in this sensitive field.