Appendix 5: Determining Egg Concentration

It is frequently necessary to estimate egg concentrations in experiments. The following procedure is simple and can give a reliable estimate of egg concentration if it is repeated four to five times.

  1. Take 100 µl of an egg suspension (well mixed).
  2. Add to 900 µl seawater (or appropriate medium).
  3. Take 10 µl of the resulting suspension (well mixed).
  4. Put on microscope slide.
  5. Count total eggs in drop.
  6. Multiply by 1000 to get eggs/ml in original sample.
  7. A 1% suspension is approximately 4 x 103 eggs/ml.