In a transfusion setting, donor and patient are matched only for antigens of abo and rh (d) blood group systems but are not routinely tested for other minor blood group antigens. in multitransfused patients suffering from thalassaemia and sickle cell anemia, the incidence of alloimmunization to red blood cell (rbc) antigens other than abo and d is particularly high (10-46%) and it increases with repeated transfusion. accurate blood group antigen typing is an important step to reduce alloimmunization caused by blood transfusion. further, the presence of rbc alloantibodies leads to serologic incompatibility, makes the selection of appropriate units for future transfusion difficult, delays the use of a transfusion therapy and presents the risk of haemolytic transfusion reaction. hence, it is advised that transfusions given to patients who are likely to become transfusion dependent over a long period of time should be matched for antigens other than abo and rhd. haemagglutination is a gold standard method for antigen typing however in multitransfused patients; it fails to phenotype the patient's antigens due to donor rbcs from previous transfusions present in the circulation of patients. to overcome limitations of haemagglutination dna based method can be used to determine the correct antigen profile of these patients. at present, red cell genotyping for these blood group systems using singleplex pcr has successfully been performed in indian population. both the blood donors and recipients can be genetically typed for all the clinically significant blood group antigens and antigen-matched blood can be provided to the recipient. this approach could significantly reduce the rate of alloimmunization. as per previous studies, the most commonly encountered alloantibodies are produced against the blood group antigens of rh, duffy, kell and kidd systems. however, an indian study reported that after rh, antibodies against mns blood group antigens were the most commonly encountered. antigen typing of each blood group system using singleplex pcr requires more steps and becomes more time-consuming and costly than using multiplex pcr genotyping. therefore, we have aimed to develop multiplex pcr kit developed for predicting blood group genotype in multitransfused patients for common antigens of kell, kidd, duffy, rh and mns blood group system according to alloantibodies found among indian patients. it is dna based method based on polymerase chain reaction (pcr) - sequence specific pcr (ssp). this pcr assay was standardized to make it cost effective and time efficient. it is easy to perform with short turnaround time as we have multiplex fourteen targets in two pcr mixes. this pcr can be utilized in indian blood banks to know extended blood group antigen profile in patients and donors so that antigen-matched blood can be provided to blood recipients. for alloimmunized patients, it will help in antibody identification and selecting antigen-negative blood units. technology details: *assay- multiplex polymerase chain reaction (pcr) - sequence specific pcr (ssp) *blood group systems targeted- rh, duffy, kell, kidd and mnss *targetted antigens: m, n, s, s , k, k fya, fyb, jka, jkb, c, c, e, e *contents- pcr additives, allele-specific primers, internal control primers (specific for the human growth hormone gene), nuclease free water *number of reactions- 2 tubes. (14 antigens in two tubes) *dna- to be extracted by the user *intended use by- blood banks and immunohaematology testing centers