EFFECTS ON HEMATOLOGY PARAMETERS DURING COLD-STORAGE AND COLD TRANSPORT OF RAT AND DOG-BLOOD SAMPLES

A sample surveillance programme is scheduled to be conducted on measur ement methods of haematology parameters which will include the partici pation of over 70 facilities. In preparation for that programme, a pre liminary study was conducted, at five of the facilities, on the effect s of cold storage and transport on rat and dog blood samples. The bloo d samples used in this study were taken from healthy, untreated rats a nd dogs from stocks held at each facility, and were anticoagulated wit h EDTA-2K. The blood samples were stored undisturbed at 4-10 degrees C . The effects of transporting samples were also investigated by placin g aliquots of the same samples in a cooler (4-13 degrees C) containing a cold insulator. Red blood cell counts (RBC), total white blood cell counts (WBC), haematocrit (HCT), haemoglobin (HGB) and platelets (PLT ) were measured twice for each sample, i.e,, fresh and 24 hours later, and these results were compared. Although blood sampling conditions w ere similar for all facilities, each facility employed its own method with respect to the analysis. Automated haematology analysers used inc luded the Toa Sysmex E4000/CS, Toa Sysmex E5000, Coulter S-Plus STRK, Technicon H1 and Nihon Kohden MEK-4500. In the case of rat blood samp les, measured values after undisturbed cold storage, fluctuating by -2 to +1% in comparison with values before storage. Measured values afte r cold transport fluctuated by -2 to +7% in comparison with those befo re transport. It was concluded, for rat blood samples, that neither st orage condition had a significant effect on the results. In the case o f dog blood samples, RBC, HCT and HGB values fluctuated by +1 to +2% a nd 0 to +2% in comparison with prestorage and pretransport values, res pectively. They were not, therefore, significantly affected by undistu rbed cold storage or cold transport. However, WBC values increased by +18% after undisturbed cold storage and by +18% after cold transport. Conversely, PLT values decreased by -20% both after undisturbed cold s torage and cold transport. It is known that dog blood samples are affe cted by cold storage, and a similar trend was observed in this study. On the basis of these results, it was concluded that the distribution of rat blood samples for the conduct of a sample survey of analytical methods under cold storage is suitable, and that it will be necessary to have the samples prepared at a single facility.