The max i have done is 100uL.

I attached the paper its published in below.

we would monitor the size of the growing tumor and treat when at 300 to 400 mm3, using a insulin suryinge to do injections, slowly.

Best Wishes!

Tumor model, immunotherapy, and isolation of tumor-infiltrating T lymphocytes

Tumors were induced behind the neck just above the scapula by s.c. injection of 1 × 106 4T1 mammary carcinoma cells to BALB/c mice or injection of EO771 mammary carcinoma cells to C57BL/6 and AhR KO mice. Tumor growth was monitored and tumors were treated upon reaching 300–400 mm3 in size with a single intratumoral injection of 4 mg of each preparation of IL-12 and GM-CSF particles (equivalent to 1 μg of each cytokine). In some studies tumor-bearing mice were treated with a single intratumoral injection of 1-methyl tryptophan (1MT; the D/L racemic mix, 4 mg/ml in 100 μl; Sigma-Aldrich) as previously described

Hi Charles,

Many thanks for sharing the article. From you experience, did you observed important necrosis/ulceration in the grafted tumour? Any idea on how to avoid or reduce this?

Would you mind clarifying the slow administration, please? Did you treat in the tumour or at the periphery?

Many thanks in advance

Best regards

Sabrina

Hi Sabrina,

The 4T1 model does a poor job at self-vascularization and will typically undergo spontaneous necrosis even without treatment. I previously compared luciferase luminescence (viable cells only) versus tumor areas (all cells) and noted that tumor challenge dosage can limit the extent necrosis occurs. Attached is a titration experiment showing that spontaneous necrosis is less severe with lower starting dosages. Potential solutions to your issue include:

1) Lowering your tumor challenge dosage

2) Changing from intratumoral to peritumoral injections

3) Changing models (e.g., Pymt-MMTV) to something that vascularizes better

Good luck!

Hi Brett,

Thank you so much for your feedback. This is very helpful. I will discuss these points with our team.

Best

Sabrina

Hello Brett,

Based on your answer about : 2) Changing from intratumoral to peritumoral injections.

How to do peritumoral injections? If it is subcu, I just inject around the tumor, not inside the tumor?

Thanks.

Best,

Limei

Hi Limei,

You are correct, it is essentially a subcutaneous injection that does not stab into the tumor with the syringe needle.