Flocks form a tight sphere-like formation in flight, frequently expanding and contracting and changing shape, seemingly without any sort of leader.
H69/41d cells have a distinct morphology: while H69 cells are non-adherent cells that form ragged aggregates, the variant cells, while also non-adherent, form tight spheres reminiscent of those seen with stem cell populations (Figure 5A).
Cell aggregates were seen within 3 days after isolation, and tight spheres were formed on Day 6.
However, after one to three passages in USSC growth mediumACF cells start to form small clusters, which become tight spheres after a further 24 hours.
MCF-7 cells alone formed tight spheres within the gel of about 30 cells in size, whereas normal luminal cells (both primary and HB4a) grew primarily as single cells or small loosely cohesive groups.
"It's a very, very tight communal sphere here and yeah it's just frustration at the moment waiting for the heads up to go ahead and do stuff," Mr. Short said.
Morphologically, primary spheroids have an asymmetric appearance versus primary neurospheres that grow as tight symmetric spheres.
The structure of mycelial pellets can range from loose, irregular aggregates, often with protruding hyphae (termed "fluffy" pellets), to tight, compact spheres [ 36].
In agreement with the data presented in the previous paragraph, we found the Sca-1+ cells formed tight compact spheres whereas the Sca-1− cells remained mostly independent, occasionally forming loosely attached chains of cells (Fig. 2F,G).
Ten days after plating, spheres (tight, spherical, nonadherent masses >40 μm in diameter) per well were counted, and at least 100 spheres per group were measured.
