I have recently resuscitated a liquid nitrogen frozen human bone marrow stem cells passage 0 sample into a t75 tissue culture flasks. The strange thing is that cells are not attaching to the plate after at 4 days. There were "things" attached to the flask bottom which are rounded -> unusual because these stem cells are supposed to have a fibroblastic appearance. The stranger thing is that these cells are exposed to fresh complete media similarly used for the same type of cells grown in other t75s. All underwent the same procedures, the rest survived yet this failed. I'm currently troubleshooting because there are no more available cells for this sample and it cost us a loss of $2000.
All brains out there, whats your take on this issue? what could possible have happen?