Species Identification of Raw and Boiled Shrimp by a Urea Gel Isoelectric Focusing Technique

Isoelectric focusing (IEF) using 9.2M urea and 6.2% (v/v) ampholytes in a polyacrylamide gel was used to separate protein banding patterns for species identification of pink, white and rock shrimp. A 17-hr focusing time was used. IEF of water extracts of raw shrimp showed excellent banding patterns useful for distinguishing each shrimp species. For cooked shrimp, water and sodium dodecyl sulfate (SDS) were better protein extractants. Detection of shrimp species in a mixture was difficult due to similar banding patterns between closely related species.