Evaluation of saphenous venipuncture and modified tail-clip blood collection in mice

Abstract

The purpose of this study was to evaluate the effects of 2 methods of blood collection in unanesthetized mice. The saphenous venipuncture method was compared with a modified tail-clip technique that requires minimal restraint. Mice were evaluated through behavioral observation and plasma corticosterone levels. The results showed that the 2 methods produced similar corticosterone responses and that the tail-clip method produced fewer behavioral reactions. In addition, the effects of saphenous venipuncture method appeared to be dependent on the handler's technical expertise. When a series of 4 blood collections were performed over 1 wk, the 2 methods yielded similar corticosterone levels that did not increase over time. Some of the behavioral signs appeared to increase over the series of blood collections obtained by the saphenous venipuncture method. Serial complete blood counts showed that the tail vessels yielded higher total white blood cell, neutrophil, and lymphocyte counts than did the saphenous vein. Neither method appeared to cause stress-associated changes in the leukogram after serial blood collection. Overall, the effects of modified tail-clip method were similar to those of the saphenous venipuncture method in unanesthetized mice.

Figure 1.

Modified tail-clip technique. Demonstration of the minimal restraint used during the modified tail-clip blood collection procedure.

Figure 2.

Effect of blood collection technique on plasma corticosterone levels. Blood was collected from mice by either saphenous venipuncture or the tail-clip technique. The average plasma corticosterone level for the saphenous venipuncture group did not differ from that of the tail-clip group. n = 13 per group.

Figure 3.

Effect of technical expertise on plasma corticosterone concentrations. To analyze the effect of technical expertise on corticosterone levels within each technique, an expert or novice handler collected blood from mice. (A) For the saphenous venipuncture group, the mean plasma concentration was significantly higher (*, P < 0.05) when a novice handler performed the blood collection. (B) However, the mean plasma level obtained by the tail-clip method was not statistically different between novice and experienced handlers. n = 5 to 8 per group.

Figure 4.

Effect of serial blood collection on plasma corticosterone levels. Blood samples were collected from mice on days 1, 3, 6, and 8. The daily mean plasma corticosterone concentrations obtained for the saphenous and the tail-clip groups did not differ significantly. n = 8 per group.

Figure 5.

Effects of serial blood collection on complete blood counts. Complete white blood cell counts performed on serial blood samples revealed significant (*, P < 0.05) differences between the saphenous venipuncture and tail-clip methods for (A) White blood cell (WBC) counts, primarily because of increases in (B) neutrophil and (C) lymphocyte counts. However, for a given technique, there were no significant changes over time. n = 8 per group.