Adding enhancer

[phytogems]

My friend emailed me, to enhance my sowing media I should add coconut water per final liter. What does the word PER FINAL LITER means? Should I add the enhancer after sterilizing the media or add the enhancer after all ingredients are mixed then sterilized it or other interpretation for this matter. Please advise....

[kmarch]

I think your friend is the one who can best clarify what he/she meant by "per final liter". I'd email the friend back and ask them to explain.

[Andrew]

It probably depends upon context but where a protocols refer to a volume or mass of a component to be added per final litre/final volume of 1 litre it typically means that you need to add the reagent and then make up the volume to 1 litre rather than adding adding the reagent to 1 litre of solution. ie 20ml coconut water/final litre would mean that you add enough media salt plus agar to make 1 litre of media, add 980ml of water and then add 20ml of coconut water (final volume = 1 litre). You friend should be able to clarify this.

Please note: if you are adding non-sterile ingredients (eg coconut milk, banana pulp etc) to your media after you have sterilised it you are probably going to introduce contamination. These ingredients need to be added before you sterilise.
Typically, only heat labile components, such as hormones, are added after heat sterilisation but these components need to be filter sterilised before adding them.

There is some good infomation on in vitro culture of orchids on the Orchid Seed Project site and the Western Orchid Laboratories site. It's well worth spending a few hours reading through the information on these sites if you are flasking orchids.