Note: PHEM buffer was developed for preserving microtubules and is used to preserve cell structure in immunostaining
References : Schliwa, Manfred, and Jonathan Van Blerkom. “Structural interaction of cytoskeletal components.” The Journal of Cell Biology 90.1 (1981): 222-235.
PHEM buffer is recommended in immunocytochemical, immunostaining studies for tissue and cell cultures.
Laboratory work has shown that the PHEM buffer allows better detection of intracellular antigens and less impact on enzymatic and biochemical reactions,
while PBS is more specific to extracellular membrane antigens,
for this reason PHEM is preferred during fluorescence markings
The use of PHEM also ensures excellent preservation of cellular ultrastructure, particularly microtubules. The buffer known as CSK, a derivative of the PHEM formulation is called CytoSKeletal (CSK) Buffer appears to improve microtubule labeling.