The cellular components of blood, namely red blood cells (RBC) and white blood cells (WBC), play a significant roles in forensic investigations. RBC, with their significance in blood typing and the estimation of time since death, serve as fundamental indicators in various crime investigation process. Conversely, WBC play a crucial role for DNA analysis due to presence of nucleated cell and serve as conclusive indicator in various crimes.
Here’s an overview on forensic relevance of RBC and WBC:
Red blood cells (RBCs)
Red blood cells (RBCs), also known as thrombocytes, have several forensic importance:
Blood Typing
- Principally blood typing is based on the presence or absence of specific antigens on the surface of RBCs.
- Different blood types have distinct combinations of these surface antigens.
- This information can be crucial in forensic investigations, especially in cases involving bloodstains or blood samples found at crime scenes and can help match samples to potential suspects or victims.
Estimating Time Since Death
- Changes in RBC morphology and hemoglobin degradation can provide clues about the time since death.
- Hemoglobin undergoes a series of color changes during decomposition, which can help forensic investigators estimate the postmortem interval.
Reference: Estimation of time since death from morphological changes in red blood cells of human cadaver
Note: Despite the fact that blood is a great source of DNA, red blood cells do not contain DNA since they are nucleus-free. Instead, white blood cells in the blood are the primary source of the DNA.
White blood cells (WBCs)
White blood cells (WBCs), also known as leukocytes, have several forensic importance:
DNA Analysis
- WBCs contain DNA that can be extracted and analyzed for forensic objective.
- DNA profiling of WBCs can be used for individual identification, particularly when blood samples are collected from crime scenes or from unidentified victims.
Estimating Time Since Death
- Changes in the composition and activity of WBCs can provide information about the time since death.
