Pisano Test

Pisano method is an ultraviolet spectrophotometry which is used in the spectrophotometric assay of metanephrines in diagnosing excess catecholamine in urine.

What kind of urine specimen is recommended?

24- hour urine can be collected. A random urine specimen may be applicable but it may not be accurate as to the representation of the total catecholamine secretion for the day. Proper specimen collection must be observed and the sample container must be light and opaque and must contain 10mL of 6N HCl fo preservation of catecholamine metabolites present. In 24-hour urine specimens, the volume is measured and a partial amount is used for assays. Specimens for assays can be frozen until it is ready for testing.

What are other assays aside from spectrophotometric assay can be used in the diagnosis of urinary metanephrines?

Fluorometry, gas chromatography, immunoassay, and radioenzymatic methods.

How is spectrophotometer assay done and what is the role of Pisano method?

"The spectrophotometric assay for the metanephrines is performed by extraction and then subsequent oxidation of the compounds to form vanillin which can be measured by ultraviolet spectrophotometry" -John Bernard Henry, 19th Ed.