Determination of ABO Blood Groups and Rh Typing from Dry Salivary Samples

A unique blood group is a characteristic every individual possesses. Blood group antigens like A, B, D, H, etc., are found to be present on the cell surfaces of red blood cells (RBCs). Besides blood, these are also secreted in various body secretions like semen, sweat, amniotic fluid, and saliva. Blood grouping has several applications in forensic sciences and is also a major part of routine medical investigations. Presence of these antigens in saliva is dependent on the secretor status of an individual. Saliva samples at the crime scene are very crucial, as they help in deoxyribonucleic acid typing, sex determination, bite mark analysis, and blood grouping. Dried salivary samples are often obtained in more number of cases as compared with the wet form, due to the variable time lapse between the occurrence of the crime and the start of the investigation. Blood grouping from these samples proves to be very efficient. Thus, the present study aims at evaluating the accuracy of ABO blood group determination and Rh typing from dried salivary samples. Also, the study would establish the use of saliva as a noninvasive technique in routine blood examinations, especially in children who have needle phobia.

Blood grouping and Rh typing were performed on the dry salivary samples obtained from the 47 subjects using the absorption-inhibition technique. This was then compared with the results obtained using extraction socket blood and evaluated.

The present study showed a 100% positive correlation for ABO blood grouping, but a mere 14.81% positive correlation for Rh typing between the dried salivary samples and the extraction socket blood.

Dried salivary samples can thus be put to immense use in several areas of forensic investigations. It could also help in developing alternate methods for routine blood investigations in children and adults.How to cite this article: Velani PR, Shah P, Lakade L. Determination of ABO Blood Groups and Rh Typing from Dry Salivary Samples. Int J Clin Pediatr Dent 2018;11(2):100-104.