96 well plate volume, per well and per plate
Overfill a well and it cross contaminates its neighbors. Underfill it and your assay runs dry. The two numbers that matter are total volume and working volume, and they are not the same.
Total volume vs working volume
Total volume is what a well holds filled to the brim. Working volume is what you can actually pipette, mix, shake, and seal without spilling, typically 60 to 80 percent of total. Spec sheets lead with total volume because it is the bigger number. Plan your assay on working volume, leave headroom for mixing and for the meniscus shift when a plate is sealed and frozen, and your volumes will survive contact with reality.
The whole plate number
Multiply per well by 96 for the full plate: a 2 mL class deep well plate holds roughly 200 mL across the plate, a standard assay plate roughly 30 mL. The whole plate figure matters for reagent ordering and for reservoir sizing when a liquid handler fills a plate from one trough.
Typical 96 well volumes by plate type
| Plate type | Total volume per well | Sensible working volume |
|---|---|---|
| Deep well, 2 mL class | About 2.0 to 2.4 mL | 1.0 to 1.8 mL |
| Deep well, 1 mL class | About 1.0 to 1.2 mL | 0.5 to 0.9 mL |
| Assay, flat bottom | About 0.3 to 0.4 mL | 0.1 to 0.3 mL |
| PCR | 0.1 to 0.2 mL | Reaction volume per protocol, usually 5 to 100 microliters |
| Filter plate | 0.35 to 2 mL by type | Leave headroom for vacuum draw and filtrate |
| Cell culture | About 0.3 to 0.4 mL | 0.1 to 0.2 mL media per well, typical |
Ranges cover common plates. Individual products vary; confirm the exact plate before a validated run.
Related guides
Common questions
How many microliters are in a 96 well plate well?
Anywhere from about 100 microliters in a PCR well to about 2,400 microliters in the largest deep wells. The common storage answer is the 2 mL class deep well; the common assay answer is 300 to 400 microliters total.
Why does my recovered volume come up short?
Dead volume: liquid clings to walls and sits below the pipette reach, worst in flat and square corners. V bottom and round bottom wells recover more. If recovery matters, pick the well shape for it, not the volume class.