What is a microplate?
A flat plate with wells in a grid, each well a small test tube that shares its walls with its neighbors, built to one standard footprint so any instrument can hold any plate.
A microplate (also called a microtiter plate or well plate) is a flat plastic plate containing many small wells arranged in rows and columns. Each well holds a sample, a culture, or a reaction, and because every microplate shares the same outside dimensions, plate readers, washers, shakers, incubators, and robots can all handle the same plate without adjustment.
The standard underneath every format
The ANSI/SLAS standards fix the footprint at 127.76 by 85.48 mm and define how wells are positioned from the plate corner. Well counts double and halve along the family: 6, 12, 24, 48, 96, 384, 1536. The 48 well plate sits at 6 rows of 8 with wells on a 13.08 mm grid, exactly halfway between 24 (18 mm) and 96 (9 mm), which is why multichannel pipettes and handlers move between them with a spacing change rather than a redesign.
The 48 well plate in numbers
- Wells: 48, in 6 rows (A to F) by 8 columns
- Well spacing: 13.08 mm center to center
- Footprint: 127.76 by 85.48 mm, the ANSI/SLAS standard
- Culture well: about 11 mm across, 1.6 mL brim, 0.95 cm2 growth area
- Deep well: square or rectangle wells, 4.8 to 7.5 mL brim, polypropylene
Why the middle format exists
Every format in the family trades wells against volume. At 384 and 96 the trade favors throughput; at 24 and below it favors material per well. The 48 well plate is the balance point for work that needs both: an experiment with real replication that still produces enough cells or extract per well to measure downstream. Labs that run both 24 and 96 usually find 48 quietly taking over the experiments in between.
Who uses 48 well plates
- Cell culture labs: dose responses, transfections, and condition screens with harvestable material per well.
- Bioprocessing and screening groups: small-scale culture and extraction in deep well plates, shaken like a plate and harvested like a tube rack.
- Analytical labs: sample prep and filtration batches in the 5 mL class.
- Teaching labs: a class set of conditions on one plate per student pair, at a scale where pipetting is still forgiving.
Related guides
Common questions
Is a 48 well plate a microplate?
Yes. A microplate is any plate in the standard footprint family, from 6 to 1536 wells. The 48 well plate is a full member: same outside dimensions, same instrument compatibility, wells on the 13.08 mm grid defined for the format.
What is the difference between a 48 well plate and a 96 well plate?
Well count, well size, and what the well is for. A 96 well holds microliter volumes for assays read in place; a 48 well holds about three times the growth area and, in deep well form, milliliters for work you take back out. Same footprint, different job.
Why are microplates all the same size?
Because instruments are built once and plates are bought forever. The shared ANSI/SLAS footprint means a reader, washer, or robot arm made this year handles plates from any maker, and a protocol written around one brand survives switching suppliers.
What does 6 by 8 mean on a 48 well plate?
The well layout: 6 rows lettered A to F and 8 columns numbered 1 to 8. Wells are named by row and column, so F8 is the corner well in row F, column 8. Plate maps and plate map makers use the same addresses.
Are all 48 well plates the same?
No. They share a footprint and grid, but differ in well shape (round, square, rectangle), material (polystyrene for culture, polypropylene for deep well and filter plates), surface treatment, and height. Fit and function follow those details, not the well count.