384 well plate knowledge base
Every question the 384 guides answer, organized by topic, plus the two density problems covered in full here: cross-talk and the edge effect at 384.
At 384 wells, most questions are about living with density: exact volumes, tight dimensions, automation discipline, and the two failure patterns small wells invite. This page indexes the answers across this guide and the sister guides, and treats cross-talk and the edge effect at 384 in full below.
Start with the basics
- What is a microplate? The idea, explained from the 384 format, with the format in numbers.
- How to choose a 384 well plate: well shape, height, and sealing.
- 384 vs 96 well plates: the cost, throughput, and handling trade.
- The 384 well plate guide: types, volumes, and who should switch.
Dimensions and volumes
- 384 well plate dimensions: footprint, pitch, heights.
- Volumes on the homepage: working volume per well, total volume by type, and well surface area, answered in the common questions.
- 96 well plate volumes: the comparison numbers when a run spans both formats.
By assay and readout
- Absorbance: clear plates; color logic on the 96 well types page.
- Fluorescence: black plates, and the cross-talk section below.
- ELISA at 384: miniaturized immunoassays; start with the complete guide to ELISA plates.
- Cell assays at 384: growth areas and seeding in the cell culture formats guide.
Automation and handling
- 384 plate map templates and the plate map maker: layout before liquid.
- Sealing for storage: films, mats, and heat seals, which matter as much at 384 storage as at 96.
- Handling and sealing choices in the buying guide.
Cross-talk at 384
Cross-talk, signal from one well registering in its neighbors, gets worse as wells shrink. The 4.5 mm pitch puts walls closer together and the walls themselves are thinner, so light piping through the plastic has a shorter path, and high-signal assays (chemiluminescence above all) show inflated neighbors sooner. The general mechanism is covered in the microplates knowledge base; the 384-specific levers are these: run fluorescence in black plates without exception, treat white plates for luminescence as a sensitivity purchase paid for with some cross-talk, confirm the reader masks for 384 rather than assuming the 96 aperture logic carries over, and test any seal you read through at this density, because a clear seal bridges 384 wells optically just as it does 96, only closer.
The edge effect at 384
The perimeter problem is arithmetic at 384: 76 of the 384 wells are edge wells, a fifth of the plate, and each holds microliters that evaporate proportionally faster than a 96 well volume. Edge wells concentrate, drift in pH and osmolarity, and read differently from the center, in cell and biochemical assays alike. The mitigations that work: seal plates for every incubation, keep incubator humidity high, fill unused perimeter wells with medium or buffer so the working wells are not the edge, rest seeded plates about an hour at room temperature before incubating, and randomize positions so a residual pattern cannot align with your groups. Sacrificing the perimeter entirely is the expensive last resort; at a fifth of the plate, the steps above are worth doing first. The full treatment is in the microplates knowledge base.
Related guides
Common questions
Where can I find the dimensions of a 384 well plate?
On the dimensions page of this guide: the standard footprint is 127.76 by 85.48 mm, the same as a 96 well plate, with wells on a 4.5 mm pitch in 16 rows by 24 columns. Total height varies by type and is listed per format there.
How do I stop edge wells drying out in a 384 well plate?
Seal the plate for incubations, keep humidity high, and fill unused perimeter wells with medium or buffer so working wells are not on the edge. Perimeter wells are 76 of 384, so the fix matters more here than at 96.
Does cross-talk get worse in 384 well plates?
Yes. Wells sit closer (4.5 mm pitch) with thinner walls, so light from a bright well reaches its neighbors more easily. Black plates for fluorescence, care with white plates in luminescence, and a reader masked for 384 keep it down.
Can I run an ELISA in a 384 well plate?
Yes, miniaturized ELISA is routine: volumes scale down to tens of microliters per step. Check the kit first, because many kits are validated and specified for 96 only, and their stated volumes and timings govern.
What is the growth area of a 384 well for cell culture?
About 0.06 cm2 per well, roughly a fifth of a 96 well. Seeding therefore runs to several thousand cells per well for many adherent lines at confluency.