Iron Quantification in Cerebrospinal Fluid

Several studies have attempted to measure iron levels in cerebrospinal fluid (CSF), which is believed to contain very low levels of iron. In general, the assays used in these studies suffered from poor reproducibility or lack of sensitivity. In the present study, an assay was developed that enables iron quantitation in CSF using 150 μl of undiluted CSF, sample digestion, dot blotting, Perls' histochemistry, 3,3′-diaminobenzidine enhancement, and densitometry. Inter- and intraassay variability was low and sensitivity high (279 pg iron in 100 μl). There were negligible readings for standard curves utilizing copper in place of iron. The iron content in eight normal CSF samples was 61.01 ± 18.3 (SD) μg/liter, and in nine normal sera it was 1332.7 ± 408.2 (SD) μg/liter. The present assay enables reliable measures of iron levels in biological samples. This assay should enable future studies that address how CSF iron levels change during the course of various disease states.