Millicell® Ultra-Low Attachment (ULA) Plate FAQs
With 3D cell culture, researchers can mimic the in vivo environment for research applications such as drug development or cancer studies. Millicell® Ultra-low Attachment (ULA) plates promote the self-assembly of scaffold-free, uniform spheroids for 3D cell culture experiments. Here, our scientists answer your frequently asked questions about Millicell® polystyrene 96-well round bottom ultra-low attachment 3D cell culture plates.
What is the advantage of using a U-bottom versus a flat bottom microplate for forming spheroids?
The unique Millicell® bottom design generates single, uniform, spheroids that are centered within each well of the plate. These types of plates have demonstrated, reliable performance in spheroid formation and 3D screening assays. Flat bottom plates often generate single aggregate formation of spheroids, which ultimately leads to multiple, non-uniform sized cell aggregates that are not evenly distributed within the well.
What 3D spheroid applications can be performed in ultra-low attachment (ULA) plates?
- Fluorescent image analysis – cell division in spheroids
- Fluorescent image analysis – live/dead cell assay of spheroids
- Evaluations of drug efficacy – response of co-cultured spheroids to drugs
- Analysis of anti-cancer drugs – targeting the interior microenvironment of spheroids
- Evaluation of drug efficacy – quantitative evaluation of spheroid size
- Evaluation of drug efficacy – response of spheroids to a drug
- Cell counting – measuring the number of cells in spheroids
What are the dimensions of the Millicell® ULA plate?
Can I use a liquid handler or automation with these plates?
These plates can be used with automation for initial cell seeding. It is not advisable to use automation after cell seeding because of the ultra-low attachment, which prevents cell adherence.
What is the maximum volume for this plate?
The maximum volume is 300 µL, however we recommend a working volume less than 250 µL.
How do I control the spheroid size?
The size of spheroids is dependent on factors including initial plating density, cell type, duration of growth phase in 3D ULA culture, and the user desired size of spheroid at the time of assessment. Maximum seeding density will vary depending on cell type.
How do I seed cells as a single cell suspension if my cells keep aggregating/clumping?
If cells are particularly sticky/clumpy, a 40 µm cell strainer may be required to achieve a single cell suspension.
How many spheroids should be generated per well?
There should only be one spheroid forming in each well of the plate.
Will evaporation be an issue?
The plate lids specially fit the plate, with rings designed to frame the top of each well.
Why might spheroids have trouble forming, or form multiple aggregates?
If cells are seeded manually, care should be taken to avoid touching the bottom or sides of the microwells with the pipet tip to avoid damaging the ULA surface coating. Make sure to start with a single cell suspension to avoid pre-existing aggregates.
How long does it take for cells to form a 3D spheroid?
Many cell lines will form spheroids within a 24-hour period. Some cell lines form looser aggregates and may require fibroblast co-culture or additional media supplementation such as methylcellulose. Optimization is required for each cell type.
How do I change the medium of spheroid cell cultures?
We recommend that you change half the volume of the medium using a micropipette gently. There is a risk the spheroid may be removed when changing medium, as it is not adhered to the well. Do not set the pipette tips close to the spheroid. Slowly aspirate liquid so not to disturb the 3D cultures.
Can I perform in-plate assays, staining, and imaging?
Millicell® ULA plates are optically clear, with bottom wells. There are many in- well assays that can be performed with this plate, including imaging directly in the plate.
What is the depth for plate reading?
The total height of the plate is 14 mm. The depth (top-down) of the well is 10 mm. The well bottom (bottom-up) has an elevation of 4 mm. The polystyrene thickness at the well bottom is 1.1 mm.
Do the plates exhibit well-to-well crosstalk?
We have not observed fluorescent or luminescent crosstalk between wells in this specific plate. However, we advise you use caution, as this is a clear plate with transparent well walls.
What sterilization method is used for packaging?
We use gamma irradiation after packaging our products. Please contact customer support for more information.
Are there any special storage conditions?
We recommend you store Millicell® ULA plates at room temperature, in a low humidity location away from direct sunlight. Do not use if the package is wet or damaged.
What is the chemical resistance of the Millicell® ULA plate?
Organic solvent compatibility:
Surfactant compatibility:
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