Small-bore pipettes

MATERIALS

Bunsen burner

Forceps, small

Pencil, diamond-point

Tubes, capillary, borosilicate glass, 10-cm length, 1-mm OD, 0.5-mm ID (e.g., Clark GC 150-T10 or equivalent)

Small-bore pipettes are used for embryo transport and to inject embryos in the genital tract.

1. Hold a glass capillary tube at both ends. Heat at the center of the capillary by rotating the capillary in (or near) the flame of the Bunsen burner until the capillary melts.
2. Immediately after the capillary starts to melt, quickly remove the capillary from the flame. Pull it straight to obtain a pulled capillary in the center region.
3. Cut the capillary in the pulled region with the diamond-point pencil.

These capillaries can be used for most embryo transport applications and transfer of embryos to the uterotubal junction.
4. If required, prepare capillaries for transferring embryos to the oviduct:
- i. Heat the capillary (from Step 3) with the tip of the flame.
- ii. Approximately 1 cm from the tip, bend the capillary to an angle of 20° relative to the long axis.