ABSTRACT
Sixty-six cerebrospinal fluid (CSF) samples were selected from Thai patients admitted to Siriraj Hospital with diseases involving their nervous systems. These patients’ clinical features were considered recovered and they had no neurological diagnosis when the CSF was taken for study. The selected samples were clear-colourless with no cells CSF. Total protein was measured by modified method of Henry, Sobel and Segalove using 12.5% Trichoroacetic acid to precipitate protein. Statistical analysis of the reference values were 13 to 42 mg/dl (mean = 27.34, standard deviation = 7.31). There was no statistical association between total protein and age group, namely, 13-25, 26-50, 51.48 years (p = 0.86, Analysis of Variance). There was no statistical difference between protein and sex (t = 0.4863, p > 0.05). The coefficient of variation of 10, 30, 50 and 100 mg/dl were 6.49, 8.22, 3.52 and 2.78 percent respectively which were acceptable precision. Therefore the reference values of total CSF protein can be established for Thai, any age and sex and can be used as predictive values for neurological diseases.