Introduction: Determination of the changes of blood samples is an important subject. The time passing from changing of normal morphology of WBCs to the un-identification period is useful in the determination of the age of in vitro storage blood which in turn helps in determination of post-mortem intervals.
Materials and Methods: This study was done to demonstrate the light microscopic and ultrastructural changes occurring in white blood cells (WBC in vitro samples at different time intervals. Light microscopic examination of blood films using Hematoxylin and Eosin (Hx & E), semithin sections stained with toluidine blue, and electron microscopic examinations were done at intervals of (0, 6, 12, 24, 48, and 60 hours) for in vitro blood samples left at room temperature.
Results: Concerning the morphological changes in different WBCs, it was observed that neutrophils had normal structure at zero- and 6-hours post-storage. Degeneration was observed at 12-hours and progressed at 24-, 48-, and 60-hours. Degenerative changes include pyknosis, and irregularity in the nuclear shape, vacuolation, pale-stained, and decreased amount of cytoplasm. At 60 hours most of cells are completely degenerated and cannot be discriminated from other WBCs. Ultrastructurally, it was noticed that the degenerative changes were observed in neutrophils after 12-hours post storage. They progressed gradually at 24-and 48-hours till they became completely unidentifiable at 60hours. Eosinophils showed degenerative changes at 12-, 24-, and 48-hours then they became completely degenerated and un-recognized after 60-hours. In addition, monocytes began to show degenerative morphological changes at 12-, 24-, 48-, and at 60-hours most of them completely degenerated. It was observed that lymphocytes were the most resistant cells as they were the only cells that could be detected at 60-hours by semithin sections.
Conclusion: It was concluded that the morphological changes of WBCs of in vitro blood samples could be an indicator of the age of the blood.