The investigation of a failure of proficiency showed that certain saline solutions are inappropriate for use in blood group serology tests. In particular, it was found that solutions of unexpectedly low pH and/or those autoclaved and stored in plastic containers could severely compromise the sensitivity of the antiglobulin test when used as wash solutions. The observed loss of sensitivity ranged from a reduction in titration score to a complete failure in the detection of clinically significant blood group antibodies. It is suggested that careful consideration should be given to the source, pH, and storage container of saline solutions intended for use in serological tests and that improved standardization and sensitivity could be achieved by using phosphate-buffered saline pH 7.0 to 7.2 for all such purposes. It is recommended that unbuffered saline solutions of pH less than 6.0 should not be used for serological testing.
Magín Pont MestresJoan Francesc Pont Clemente
Ernesto Ibarrondo Fernández de Leceta