2.3. Enzymatic activity
For each sampling time, three samples of 150 larvae until 10 dph,
50 larvae until 20 dph, and 20 larvae until 40 dph were used for
enzymatic analyses. Because of the difficulties associated with
dissecting and removing the digestive tract of small larvae, whole
body homogenates were used for enzymatic analyses in larvae
younger than 16 dph. After this age, the larvae digestive system was
dissected on a glass slide supported on a frozen mini-table.
Each sample was homogenized with a tissue grinder in 1 mL of
distilled water chilled to 4 °C. A subsample of the homogenate was
stored at −80 °C until later analysis of leucine aminopeptidase
activity. The remaining sample was centrifuged at 14,000g for 30 min
at 4 °C, and the supernatants were stored at −80 °C until analysis.