Rodent Dosing Calculator

Diehl et al. (2001) Good-Practice Volume Limits

The Diehl guide is the most cited source for rodent injection volumes in IACUC and AAALAC documentation:

• PO (oral gavage): 10
• IP (intraperitoneal): 20
• SC (subcutaneous): 10 (single site)
• IV bolus (lateral tail vein): 5
• IM (intramuscular): 0.05 (per site, very small)

• PO: 10
• IP: 10
• SC: 5 (single site)
• IV bolus: 5
• IM: 0.1 (per site)

These are *practical good-practice ceilings* — not toxicity thresholds. Some studies justify higher volumes when the vehicle is well-tolerated, but exceeding the Diehl limit always requires explicit IACUC review.

Practical Draw Limits & Stock Dilution

Standard 1 mL insulin syringes have a meniscus error of ~5–10 µL. Volumes below 10 µL cannot be reliably drawn — even an experienced technician will introduce 50%+ dose variability.

When the calculator flags a volume as "below practical draw," the fix is almost always to dilute the stock. A target injection volume of 50–100 µL gives a comfortable safety margin and matches what most published protocols use for PO and IP routes.

If the stock cannot be diluted (e.g. solubility limits), consider switching to a volumetric micropipette and aspirating from a small reservoir — but this is technician-dependent and should be qualified before the study.