The inside of a cell is negative relative to the outside. This is due to a slight excess of positive charge building up on the outside of the cell membrane and a slight excess of negative charge on the inside. This creates a difference in electrical potential across the membrane.
However, the term "positive" or "negative" in relation to cells can also refer to other properties, depending on the context. For example:
-
Hormone Receptor Status in Cancer Cells: Cancer cells are often described as hormone receptor-positive or hormone receptor-negative based on the presence or absence of specific receptors. (https://www.cancer.org/cancer/types/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-hormone-receptor-status.html)
-
Immunology: In immunology, terms like "CD19-positive" or "T cell-negative" are used to describe the presence or absence of specific cell surface markers. (https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-blinatumomab-consolidation-cd19-positive-philadelphia-chromosome-negative-b-cell, https://www.ncbi.nlm.nih.gov/gtr/conditions/C1832322) Mast cells can exhibit both positive (pro-inflammatory) and negative (anti-inflammatory) immunomodulatory functions. (https://pubmed.ncbi.nlm.nih.gov/18483499/, https://pmc.ncbi.nlm.nih.gov/articles/PMC2855166/)
-
Battery Cell Capacity: In the context of battery cells, the term "negative" and "positive" refers to the electrodes (anode and cathode). The ratio between their capacities is crucial for battery design. (https://pubs.acs.org/doi/full/10.1021/acsaem.2c00665)
Therefore, the answer depends heavily on the context. In terms of electrical potential, the cell interior is negative relative to the exterior.
