Table 3. Laboratory methods used for determination of possible senescent-cell biomarkers.

Analyte	Method	References
morphological analysis	inverted phase-contrast microscope	73
cell viability	tetrazolium reduction, microplate spectrophotometer	71
SASP	ELISA	12,68
SAHF	immunohistochemistry	12
γH2AX	histochemistry	12,68
p16, p53, and p21	histochemistry, immunohistochemistry	12
SA‐β‐GAL	histochemistry, immunohistochemistry, flow cytometry	12,68,79
autophagy	immunoblotting	72
cell proliferation	flow cytometry	73
leukocyte absolute telomere length	southern blot, PCR, FISH	68,75,76
ELISA – enzyme linked immunosorbent assay. SASP – senescence-associated secretory phenotype. SAHF – senescence-associated heterochromatin foci. γH2AX – a type of histone protein from the H2A family, a marker for activation of DNA damage response. PCR – polymerase chain reaction. p16 – cyclin-dependent kinase inhibitor 2A, multiple tumor suppressor 1. p53 – tumour suppressor gene, induces senescence growth arrest via activated p21–p53 pathway. p21– cell-cycle inhibitor, induces senescence growth arrest via activated p21–p53 pathway. SA‐β‐GAL – senescence-associated β-galactosidase. FISH – fluorescent in situ hybridization.