Freeze-fracture analysis disclosed the presence of both gap junctions and tight-junction sealing strands in the UROtsa cells cultured
on serum-free growth medium (Figure 3 A,B,C).
For example, when his group exposes the cultured
cells to brain chemicals called nerve growth factors, the cells divide normally until they fill the culture dish, gradually differentiating into mature neurons.
Bhatia's group further demonstrated that the hESCs cultured
under these new conditions maintained the same capacity to differentiate into hematopoietic progenitor cells, capable of forming all cellular components of blood.
However, the number or percentage of positive samples in a given area could not be used to quantify the contamination because quantitative spore counts were not performed when samples were cultured
, a variety of sampling techniques were used (swabs, wipes, vacuum, and air sampling), and the distribution of samples obtained was not uniform.
brain tissue from 13- to 21-week-old fetuses aborted by uninfected women, and compared what he saw to his previous observations of nervous tissue from fetuses aborted by HIV-infected women.