Estimation of Amino acid by Ninhydrin method

Aim: Estimation of Amino acid byNinhydrin method

Reagents required:

Standard: Dissolve 10 mg of glycine in 10 ml of solvent in a distilled water.

Ninhydrin: 0.2 %

Sodium citrate buffer: 0.2 M

Diluent solvent: water & n-propanol mixed in the proper amount.

Procedure for standard curve: The Ninhydrin method is being used to analyze the estimation of amino acids content. Glycine is taken as a positive control. Pipette out various concentrations into labeled test tubes & combined with 1 ml of Ninhydrin reagent solution. After an incubation period of 20 minutes in a water bath, the tubes containing the solution are allowed to cool, & 5 ml of a diluent solvent is added to each tube. After the completion of incubation period, the absorbance of the standard solution is measured at a wavelength of 570 nm using a spectrophotometer.

Procedure for estimation of amino acid in plant sample:

Sample extract: Weigh 100 mg of dry bark powder & crush it with a pestle & mortar. Mix the bark powder with a small amount of sodium citrate buffer. Transferring the material to centrifuge tubes & placing them in the Centrifuge machine, spinning them at 3000 rpm for 10 minutes. After the centrifugation, carefully collect the liquid part (supernatant) that separates from the solid material. Combining the bark extract with 1 ml of Ninhydrin reagent at different concentrations. Place the tubes containing the solution in a water bath & incubating them for 20 minutes. Following that, assess the absorbance of the sample solution at a wavelength of 570 nm using a spectrophotometer.