An elastomeric vial cap used for sealing a vial container, but allowing pipetteaccess to its containment fluid includes an annular flange portion for cappingthe vial and a sloped truncated cone portion to easily guide the pipette into thevial container. A tubular seal portion is configured to encircle the truncatedcone portion and firmly engage an inside wall of the vial container with ease ofinsertion. A center flap portion is circumscribed by a channel at its top surfacefor penetration by the pipette and has a flex portion. The center flap portionseparates around the perimeter of the channel but hinges at the channel abovethe flex portion and does not become dislodged. The ratio of the diameters of thepipette and the center flap portion is such that significant problems relatedto back-pressure and vacuum conditions do not exist during transfer of the containmentfluid.
