  Confluent populations of elongated cells give rise to ordered patterns seen
in nematic phase liquid crystals. We correlate cell elongation and
intercellular distance with intercellular alignment using an amorphous spin
glass model. We compare in vitro time-lapse imaging with Monte Carlo simulation
results by framing a novel hard ellipses model in terms of Boltzmann
statistics. Furthermore, we find a statistically distinct alignment energy at
quasi-steady state among fibroblasts, smooth muscle cells, and pluripotent cell
populations when cultured in vitro. These findings have important implications
in both non-invasive clinical screening of the stem cell differentiation
process and in relating shape parameters to coupling in active crystal systems
such as nematic cell monolayers.
