What is a deep well plate?
A microplate built for volume instead of reading: the storage and preparation member of the family, in plain language.
A deep well plate is a microplate, same standard footprint (127.76 mm by 85.48 mm, ANSI/SLAS) and same well addressing as an assay plate, but with wells several times deeper, holding roughly 0.5 to 2.2 mL each instead of the fraction of a milliliter an assay well holds. Where an assay plate exists to be read, a deep well plate exists to hold: samples are stored, mixed, grown, extracted, and frozen in it, in polypropylene that tolerates solvents and -80 °C.
The general concept is covered on the 96 well plate guide; this page defines the deep well member of the family.
What makes a plate deep well
Depth, and everything depth brings. Wells run from about 20 mm to over 40 mm deep depending on the volume class, against roughly 10 to 12 mm for an assay well. That depth changes the material (polypropylene, because the plate must survive freezing, centrifugation, and solvents that storage involves), the sealing (freeze-rated films, mats, and heat seals instead of optical films), and the job (the plate is a container and a workspace, not an optical surface). Square wells are common because they pack the most volume into the grid; round wells serve mixing and pelleting.
What deep well plates are used for
- Compound and sample storage: libraries and archives, at bench, fridge, and -80 °C, sealed for months.
- DNA and RNA extraction: the plate format magnetic bead instruments, including KingFisher systems, process in.
- Bacterial growth: cultures for plasmid prep, grown in the plate with breathable seals.
- Serial dilution and preparation: diluting, mixing, and staging samples before an aliquot moves to an assay plate.
- Protein work: expression, purification steps, and crystallization screens at plate scale.
Deep well vs a regular microplate
Same footprint, same addresses, different intent. A regular (assay) microplate is shallow, usually polystyrene, and optical: flat, clear wells made to be measured in a reader. A deep well plate is deep, polypropylene, and effectively opaque: made to contain and process, with the measurement happening later, usually on an aliquot transferred to an assay plate. Choosing between them is choosing whether the plate is the destination of the sample or the instrument of the measurement.
The choices inside deep well
Well count: 24, 48, 96, and 384, trading volume per well against throughput. Volume class: 0.5, 1, 2, and 2.2 mL per well in 96 format; pick by aliquot size plus headroom. Well shape and bottom: square wells maximize volume, round wells mix and pellet better, and pyramid (V-shaped) bottoms in square wells gather small volumes for recovery. Sterility: supplied sterile or non-sterile, marked on the pack. Instrument fit: universal plates versus plates molded for a specific instrument, where comb and magnet geometry decide. The choosing page works through these in order.
Related guides
Common questions
How much does a deep well plate hold?
By volume class: 96 well deep well plates are sold in 0.5, 1, 2, and 2.2 mL per well classes, with 384 formats in the 100 microliter class and 24 and 48 formats above 2 mL. Working volume is always lower than the class number; leave headroom for mixing, sealing, and freezing.
Can deep well plates go in the freezer?
Yes, frozen storage is what they are built for. Polypropylene is rated for -80 °C; the seal is the weak point, with cap mats and heat seals outlasting adhesive films in the cold. Leave headroom, because samples expand as they freeze.
Are deep well plates autoclavable?
Polypropylene plates are generally autoclavable at 121 °C, which is how labs sterilize a plate that was not supplied sterile. Check the maker of the specific plate, and treat instrument-specific plates by their own instructions.
What is the difference between a deep well plate and a storage plate?
Mostly the label. Storage plate is a use name: a deep well plate being used to store samples. Some catalogs also sell tube-format storage blocks under the name. Compare well volume, depth, and material rather than the title, and the two names usually describe the same object.
Can you read a deep well plate in a plate reader?
Not for quantitative work. The wells are deep and the polypropylene is not an optical surface, so readings are unreliable. Transfer an aliquot to an assay plate for measurement; the deep well plate is where the sample lives, not where it is measured.