The Sda blood group in human secretions.

The authors, employing the absorption-inhibition technique, have further extended their experiments on human biologic fluids to investigate the sid substance. It was located in tears, sweat, nasal and tracheobronchial mucus, cerebrospinal fluid, and in aqueous humor while it was not found in bile (in accordance with its absence in liver tissue). The authors emphasize the significance that the verification of the Sid substance may assume in forensic investigations with the purpose of individual diagnosis in stains of the above mentioned secretions, particularly tears, sweat, and nasal mucus.