Regularly examining the morphology of the cells in culture (i.e., their shape and appearance) is essential for successful cell culture experiments. In addition to confirming the healthy status of your cells, inspecting the cells by eye and a microscope each time they are handled will allow you to detect any signs of contamination early on and to contain it before it spreads to other cultures around the laboratory.
Signs of deterioration of cells include granularity around the nucleus, detachment of the cells from the substrate, and cytoplasmic vacuolation. Signs of deterioration may be caused by a variety of reasons, including contamination of the culture, senescence of the cell line, or the presence of toxic substances in the medium, or they may simply imply that the culture needs a medium change. Allowing the deterioration to progress too far will make it irreversible.
Most mammalian cells in culture can be divided in to three basic categories based on their morphology.
|Fibroblastic (or fibroblast-like) cells are bipolar or multipolar, have elongated shapes, and grow attached to a substrate.
|Epithelial-like cells are polygonal in shape with more regular dimensions, and grow attached to a substrate in discrete patches.
|Lymphoblast-like cells are spherical in shape and usually grown in suspension without attaching to a surface.
In addition to the basic categories listed above, certain cells display morphological characteristics specific to their specialized role in host.
Neuronal cells exist in different shapes and sizes, but they can roughly be divided into two basic morphological categories, type I with long axons used to move signals over long distances and type II without axons. A typical neuron projects cellular extensions with many branches from the cell body, which is referred to as a dendritic tree. Neuronal cells can be unipolar or pseudounipolar with the dendrite and axon emerging from same process, bipolar with the axon and single dendrite on opposite ends of the soma (the central part of the cell containing the nucleus), or multipolar with more than two dendrites.