Dear Eli

The appropriate sterilization treatments of each cultivar can vary slightly depending on the time and place of explant preparation. It is better to test the time and concentration of different disinfectants and introduce the appropriate treatment based on the lowest level of contamination.

Thank you for your reply.

The starting contamination levels are quite high for the purpose of our final goal. I seek to create a bracket for further experiments which will determine optimal protocol. Thus I seek the lethal exposure. Simple enough for single baths, but more challenging for multiple baths in sequence. Thus my question.

In the end, we will indeed seek the lowest concentration to produce optimal results given our starting material.

I hope I understood your reply correctly.

Hi Eli, your approach seems logical. However, why do you specifically decide on 75% ethanol and 0.5% sodium hypochlorite? 0.5% seems low to me and may take hours before that can be lethal... I’m also not sure if that concentration of sodium hypochlorite can prevent most contaminations.

Thank you, Andika!

I chose 75% because we have it on hand, and I have seen that concentration used (either that or 70%).

0.5% bleach was chosen based on previous experience with this genus, other genus, and literature using this species. That said, the previous attempts had low success due to high contamination. We are working with actively growing young shoots and dormant buds of Malus spp.

What concentrations would you suggest? Also, would there be a difference between Sodium and Calcium hypochlorite?