HAM test is based upon :

HAM test is based upon susceptibility of RBC&;s to complement mediated lysis in patients with PNH. HAM test is usedfbr the diagnosis of PNH (Paroxysmal Nocturnal Haemoglobinuria). HAM test (Acidified serum lysis test) demonstrates lysis of RBC after activation of complement by acid. In acidified serum complement is activated by the alternate pathway. In patients with PNH, RBC are unusually susceptible to complement, and undergo lysis when incubated with acidified fresh serum. REF : ananthanarayana 10th ed