Roche IFCC Methods for Lactate Dehydrogenase Tested for Duplicate Errors with Greiner and Becton-Dickinson Lithium-Heparin and Greiner Serum Samples

The new Roche IFCC-recommended method for lactate dehydrogenase (LD) has been reported (1)(2) to produce duplicate errors with Becton Dickinson (BD) lithium-heparin tubes with plasma separators. Separate studies (3) of Sarstedt tubes showed no such errors. To overcome and minimize duplicate errors, Roche has modified the method to incorporate a predilution step. This modified method can be used only on dilutor systems (Modular P and Hitachi 911, 912, and 917), but not on nondilutor systems (Modular D and Hitachi 747 and 902; Roche). We tested the modified method for duplicate errors and tested lithium-heparin tubes (with plasma separator) from another major supplier for duplicate errors.Blood samples were collected in three different tubes: Greiner Vacuette lithium-heparin tubes with plasma separator (prod. no. 455083); Greiner Vacuette serum tubes with plasma separator (prod. no. 455078); and BD Vacutainer PST II lithium-heparin tubes with plasma separator (prod. no. 367377). Three IFCC LD methods were set up on our Modular DP system: the Modular D, the Modular P IFCC method, and the Modular P IFCC modified method with predilution. The two LD methods on the Modular P system …