Stability of haematological constituents during simulated mail transport as measured by Coulter Counter S plus II or Technicon H 6000.

Stability of blood constituents after mail transport was examined using two different automated haematology instruments, that is, Coulter Counter S plus II and Technicon H 6000. The results were analysed by two different statistical methods. In all but four cases these methods yielded similar results. The B-LPC, B-EPC B-Hb, B-EVF, E-MCH, E-MCHC and B-TPC were stable after mail transport for 48 h when measured with Coulter Counter S plus II. In contrast, none of these parameters were stable when measured with Technicon H 6000. The differential count measured by cytochemical staining technique with Technicon H 6000 was stable for 72 h whereas the percentage of L-Lymphocytes measured with Coulter Counter S plus II was unstable after 24 h of mail transport. The criteria of stability are discussed in relation to changes of constituents that are of importance in medical decision making.