Here we describe a protocol to estimate the total particulate carbohydrate from microalgae. Carbohydrate samples are initially vortexed in 9 M H2SO4 for 15 s. The solution is diluted for a final H2SO4 molarity of 1.6 M and hydrolyzed for 3 hours at 90 °C. The hydrolysate is alkalinized by adding 12 M NaOH to the hydrolysate, the ratio of [H+] from the hydrolysate to [OH-] from NaOH is 0.82. The alkalinized hydrolysate is oxidized by ferricyanide solution. The absorbance of TPTZ-Fe2+ complex is measured in microtiter plate at 595 nm. Our method has shown high reproducibility in aldohexoses, ketohexoses, deoxysugars, aldopentoses, uronic acid and amino sugars. The linear range of response is between 0.18 to 10 µg C/mL.