Thomsen friedensreich phenomenon is ?

Ans. is 'b' i.e., Red cell agglutination by all blood group sera Thomsen-Freidenreich Phenomenon Red cell suspensions contaminated with ceain bacteria, e.g. pseudomonas aeruginosa, become agglutinable by all blood group sera and even by normal human sera. This is known as Thomsen Friedenreich phenomenon and is due to unmasking of a hidden antigen normally present on all human erythryocytes, i.e. T-antigen. Anti-T agglutinins are normally present in human sera. Such panagglutinability of red cells has occasionally been observed in persons suffering from systemic bacterial infections.