A study was carried out on shellfishes using the API (Analytical Profile Index) 20E system and the conventional method of detecting indicator organisms in faecal contamination. Results showed that the API 20E system is accurate, faster and easier to use than the conventional method. The API 20E system is a standardized, miniaturized version of conventional procedures for identification of Enterobacteriaceae and other gram-negative bacteria. It requires only 24 hours to detect the microflora present in the products. The conventional method, on the other hand, is laborious and time-consuming, requiring in most cases five days, and also subject to inaccuracies due to culture contamination.