the subject invention concerns the novel use of formyl - coa transferase enzyme together with oxalyl - coa decarboxylase enzyme for the detection and measurement of oxalate in biological samples . the use of the enzyme system according to the subject invention results in the conversion of oxalate into carbon dioxide and formate . because the production of formate is directly correlated to the concentration of oxalate present in a sample , the determination of the resulting formate concentration provides an accurate , sensitive and rapid means for detecting even low levels of oxalate .