Related Experiment Video
Updated: Sep 21, 2026

Dried Blood Spots - Preparing and Processing for Use in Immunoassays and in Molecular Techniques
Published on: March 13, 2015
Association between HBsAg and race in a mixed population of Northeastern Brazil
Abstract:
The frequency of Australian antigen carriers (HBsAg) was studied in three samples from northeastern Brazil. In sample A there were 1000 women from Tsylla Balbino Maternity in Salvador; in sample B there were 1,512 blood donors from Salvador, and in sample C there were 930 blood donors from Aracaju. In sample A, B and C the observed frequency of carriers (HBsAg) was 1.20%, 1.58% and 2.04% respectively. These differences were not significant (x22 = 2.2; p greater than 0.25). There was no association between the carrier state and sex, age, ABO and Rh blood groups, Chagas' disease and rural origin. However, the frequency of carriers (HBsAg) increases from White to Black, as follows: Whites = 0.5%; Mulattoes = 1.91%, and Black = 1.96% (x22 = 7.91; p less than 0.02).
Related Concept Videos
Blood Types
ABO blood group
ABO antigens are glycoproteins encoded by genes present on...
Blood Transfusion and Agglutination
History
The history of blood transfusion dates back to the 17th century, when early attempts were made in animals. In 1818 James Blundell, a British doctor, performed the first successful human blood transfusion. Later in 1900, Karl...
The ABO Blood Group
Antigens in the ABO Blood Group System
Antigens are substances that can trigger an immune response, leading to the production of antibodies. In the ABO blood group system,...
Rh Blood Group
Blood Typing
Antigens are protein molecules that reside on the surface of red blood cells (RBCs). The ABO and Rh blood typing systems target...
Bias in Epidemiological Studies

