Seeds may be checked for embryo presence, or absence, by placing them under a microscope. The required nutrients are provided by the fungus. Growth of seedlings is rapid. Until 1922, it was the only known method of propagating orchids from seeds. Seeds are germinated and seedlings are grown on a sterile, jelly like, culture medium containing sugars and many other nutrients.
Germination takes place without the aid of a fungus.
Since unwanted bacteria and fungi grow even faster on a sugar rich medium than orchid seedlings, all seeds, flasks, medium, and tools used must be sterilized. All the work involved, like sowing, transferring seedlings etc, is performed in a sterile environment, such as a laminar flow hood or a glovebox. Filtered through a HEPA filter, sterile air enters the cabinet and passes over the work area. Sowing of seeds is a simple procedure. Germination medium is prepared and poured into clean flasks.