2.2.2 Determination of Quality and Quantity of Sericin
Qualitative estimation of sericin was done by recording
the ultraviolet spectra on D-2750 UV-Vis
spectrophotometer (Shimadzu, Singapore) and then
determining the A-ratio. A-ratio, signifying the purity of
proteins, was determined by calculating the ratio of
absorbance of the sample at 280 nm and 260 nm. Since
nucleic acids absorb UV radiation at 260 nm and proteins
absorb UV radiation at 280 nm, A-ratio above 1.8 typically
corresponds to a sample that is free of contamination24. The
quantity of sericin in the extracted liquor was calculated by
determining the protein content by Lowry’s method using
bovine serum albumin (BSA) as a standard.