The initial cell count selected depends on the cell type/cell line and the desired size of the spheroids. Experience has shown that cell counts between 1,000 and 6,000 cells/well are suitable. To set the cell count per well for the respective experiment, it is recommended to carry out a dilution series and then determine the optimal cell concentration based on the desired parameters.
Do the plates need to be centrifuged after seeding the cells?
A centrifugation step is not recommended. Unnecessary centrifugation can even have a negative effect on spheroid formation. However, if you wish to centrifuge the cells at the start anyway, 200-300 x g for 2-5 min. should not be exceeded.
Is there a protocol for spheroid culture in the BIOFLOAT™ plate?
A general protocol for spheroid cultivation in the BIOFLOAT™ plate can be found here. The exact parameters such as working volume and cell density for seeding depend on the cell type used and the analysis method planned. Carefully optimising the growth and analysis conditions is therefore recommended.-> Handling instructions
How quickly do spheroids form in the plates?
The time required by the cells to form spheroids depends on the cell line. With BIOFLOAT™, formation has been observed after 2-24 h. It should be noted that some cells first form only loose aggregates that become increasingly dense over time, so the diameter of the spheroid may first become smaller in this initial phase.
Why do some cells form only loose spheroids?
Not all cell lines or cell types are equally suitable for forming spheroids. It may be helpful to add proteins of the extracellular matrix to make spheroid formation possible.
How long can cells be cultivated in the plate?
The maximum possible period for spheroid culture depends on the cell line. Cells have been cultivated continuously in the BIOFLOAT™ 96-well plate for over 80 days.
Are the BIOFLOAT™ plates suitable for cultivating organoids?
Spheroids, which usually consist of one or maximum two cell types/lines, should not be confused with organoids, which are more complex 3D cell cultures. The formation of organoids is a complex process that cannot be reproduced in the BIOFLOAT™ plate alone. However, previously formed organoids have been successfully cultivated in the BIOFLOAT™ plate.
Can the medium in the plate be changed without using a new plate?
The BIOFLOAT™ surface is very robust against mechanical effects caused by pipetting. It is thus no problem to change the medium in the plate several times.
Can fluorescence images be made in the BIOFLOAT™ plate?
Images of fluorescence dyes that, for example, make the cell viability in the spheroid visible, can be made in the BIOFLOAT™ plate.