7M discover the starch test

Testing a leaf for starch has to be one of the all time classic science experiments and this week 7M mastered the technique

The leaf has it's chlorophyll extracted with ethanol

The ethanol turns a deep green colour and is disposed of carefully.

The leaf is now decolourised but is very brittle so it needs washing to soften it

It is then spread out on a Petri dish

And iodine dropped onto the soft decolourised leaf

The leaves turn black if they contain starch

Mission accomplished