Several studies previously confirmed the high accuracy of K/Na ratio as cell viability indicator with K, Na and Cl being the most Orbifloxacin sensitive and reliable marks. Strikingly, these 4-(Benzyloxy)phenol results correlated very well with the classical and metabolic assays, thus confirming our results. Generally, low concentrations of intracellular potassium and high Na contents are associated to apoptosis, which can be detected in early pre-apoptotic stages by a decrease of Cl concentrations. In this regard, our results showed that an apoptotic process could be triggered from P1 to P2 and from P6 to P7, suggesting that P7 could not be viable. Moreover, high concentrations of sulfur and phosphorous and moderate concentrations of magnesium and calcium were also found at P6. From a microanalytical point of view, phosphorus is an element that is associated with cell mass and organic constituents, nucleic acids contents and the level of cellular phosphorylation, and cells characterized by a severe structural damage show a decrease in intracellular concentrations of phosphorus. Therefore, the high values found at P6 would confirm the vital status of these cells, whereas the decrease at P7 could be related to a possible structural damage of these cells. In addition, magnesium has been associated with cellular ATP levels and a concentration decrease of magnesium is correlated with a decrease in cellular ATP concentration, phosphorylation, and DNA replication. The results obtained in this work suggest that cells of the TMJ articular disc of human adults would experience a decrease in ATP content in some cell passages, especially at P7. Similarly, the concentration of sulfur was high at P6. These results must be correlated with the participation of sulfur in the metabolism of sulfated proteins, proteoglycans and glycoproteins that are very important in these cells. Finally, the lowest calcium values at P8 and the highest levels at P3 might be explained by cell viability alteration at these passages. Once we determined cell viability at different levels, we obtained an average cell viability index that provides comprehensive information about the vital status of these cells. In summary, our combined cell viability analysis approach suggests that the most adequate cell passage for use in cell therapy could be P6, implying that these cells should preferably be used at this passage. The cell viability index results found that the most viable passages were P6 and P5. In these passages we found a perfect match with high levels of proliferation, low cell damage of the cell membrane as determined by trypan blue, and high metabolic activity along with an adequate equilibrium of sodium, magnesium, phosphorous, potassium, calcium, sulfur and chlorine levels. In contrast, P2 and P9 demonstrated to be the cell passages with compromised cell proliferation, ATP levels, cell volume, synthesis of sulfated proteins and evident alteration of the K/Na pump. This combined cell viability approach is likely to be much more accurate than the use of a single method or technique to evaluate cell viability, and gives valuable information on the metabolic and structural cell status. In fact, several studies previously carried out on articular cartilage found that the use of cultured human hyaline chondrocytes could not be clinically useful Perhaps, some of these studies did not use the most viable cell passages and cell viability was determined by using single, low sensitive techniques.