Storage and Transportation of Samples for Analysis of Terminal Transferase by Indirect Immunofluorescence

Expression of the terminal transferase (TdT) antigen, as revealed by indirect immunofluorescence, was retained in samples of human acute lymphoblastic leukemia (ALL) cells, of various phenotypes, during storage at 4 degrees C for almost six months. Similar specimens of ALL cells, of common phenotype, were transported successfully by air without notable loss of TdT. The unsatisfactory outcome of earlier studies may be explained on the basis of methodologic differences alone.