Hello everyone,

My experiment involves administration of different doses of proteasome inhibitors (via i.p.) to mice and harvest lungs to measure the proteasome activity. Before I actually do the assay, I would like to seek some inputs form you. My questions are,

1. Because lungs are very soft tissue and mostly filled with air and bronchial fluid, how to obtain a fixed amount of tissue from different mice? I am thinking of mincing one entire lung lobe, spin it down at 500G for 5 min to get rid off the extracellular liquid and add assay buffer according the weight of the tissue. Any comments? Or do you recommend another way of normalization?

2. Fresh vs frozen: what is the impact on proteasome activity.

3. Although I am planning to measure the proteasome activity using 20S assay kit, is there any advantage of choosing 26S assay over 20S?

4. Any other comment?

Thank you in advance.

Raghu