Maintaining sterile conditions
In symbiotic and asymbiotic germination it is vital that all seeds, flasks, instruments and media are kept sterile at every stage of the germination procedure. If any fungi or bacteria get into the flasks they will grow much faster than our seeds or seedlings and will kill them soon. To prevent this contaminations, the flasks (inculding the media) have to be autoclaved or should be placed for 30 minutes in the oven (150 °C). The seeds or plantlets (nodes, ...) must be sterilized (e.g. with hydrogen peroxide) and transferred to the flasks without introducing extraneous bacteria or fungus.
Laminar flow hood
The laminar flow hood consists of a cabinet and a laminar air flow unit. The laminar flow unit includes an very fine filter (hepa filters) which removes all bacteria and fungi. The filtered (sterile) air flows out of the cabinet and produces a sterile area inside the cabinet.
Before using the laminar flow hood you have to sterilize the inner surface of the cabinet with 70 - 90% alcohol.
Glove box
A glove box consist of a glass box (e.g. an aquarium) which is closed on it´s open side including two openings to put your hand trough. Before you start working you have to place all necessary equipment, flasks, seeds and chemicals inside the glove box. Then close the box and spray the area inside the box with desinfection solution (e.g. alcohol).
Working above boilding water
This is the cheapest way to propagate orchids in vitro. At this technique you use the fact that steam is sterile. The size of the sterile area depends on the diameter of the used pot.
Author: Thomas Ederer