GB2198453A - Micromanipulator for embryo bisection - Google Patents

Description

2198453 - 1 MICROMANIPULATOR FOR EMBRYO BISECTION The invention relates to

a micromanipulator for embryo bisection. The bisection of mammalian embryos is a micromanipulation method enabling the division of an embryo into two halves. Following the subsequent cultivation and transfer of these halves into recipient females, the procedure serves to obtain identical twins. The bisection thus increases the number of transferable embryos, which -&.s of importance first of all for enhancing the success of work teams at animali- breeding farms in transferring cattle embryos.

Known bisection procedures use mIcromanipulators of various constructions designed as apparatus for various micromanipulating operations, embryo bisection being only one of the possibilities of their use. However, under field work conditions and seen from the aspect of breeding practice, it only bisection that is required at present. Further, the common feature of the above micromanipulators is the control of the cutting tool as carried against the embryo via a mechanism refining the movement of the human hand. Hence their complicated construction and high price.

These disadvantages are removed by a mi.cr.oman.-A.pu'La-tor for embryo bisection accordIng to the invention described below. It consi-sts of two arms, one attached to the objective of a microscope, the other arm carrying a cutting tool forming a functional whole with the movable parts of the microscope.

The micromanipulator for embryo bisection is a device working upon a new principle of embryo cutting in that the latter is carried against the cutting tool. This principle made it possible to 2 develop a simple device wh.-,.ch, after being attached to the objective of a light microscope, enables finely controlled movable parts of the microscope to be used securing thus the applicability of this coupling.

A micromanipulator according to the invention will now be described, by way of example, with reference to the accompanying d,.agraininat-L,drawings, in which:

Figure 1 is a s2de elevation of the mLcromanipu-':-a-tor; and Figure 2 is a plan to Figure 1.

The iLlUStrated micromani.Dulator COMP-t_Lses clamping jaw 2 and a second (left) interconnected by a control screw 4. on the screw 4 secures the attachment a first (right) clamping jaw 3, A control nut 5 of the jaws 2 and 3 to the objective 1 of a microscope and the clipping of an adjusting mechanism 9 to the jaws 2, 3. The adjusting mechanism 9 is formed by two arms pivotally connected to each other at one of their ends. A holding screw 7, through a piece 8, enables a cutting tool 6 to be fastened in the required position. Precision adjustment of the cutting tool 6 into the field of view of the Micro- scope is secured by the adjusting mechanism 9 through a set screw 10.

The m.-L--rDma.-i-Lpialator for emb.-yo b.se--t.Lon is fastened to the objective 1 suCh that the adjusting mechanism 9 is situated to be parallel to the longitudinal movement of the microscope stage. The cutting tool 6 fastened through the pLece 8 is poLnted by its tip to the centre of the fie'Ld of view. Its precision adjustment is ensured b.

y the movement of the micromanipulator about the axis of the objective 1, by rotation of the upper arm of the 1 3 adjusting mechanism 9 in the opening of the jaws 2,3, by the movement of the set screw 10, and by the adjustment of the position of the cutting tool 6 under the piece 8. The tip of the cutting tool 6 is used both to cut and to orientate the embryo in the drop of a medium on the support glass of the microscope. The microscope lens is thus simultaneously focused both on the embryo and on the tip of the cutting tool 6. Moving the microscope stage upward brings the embryo into contact with the tip and movLng the embryo by moving the microscope stage longitudinally, its rolling by the tip is obtained in the drop of the medium. After reaching the required position of the embryo, the cutting tool 6 is finely lifted using microscope microscrew and by moving the microscope stage the embryo is shifted under the cutting tool 6. Again, using microscope microscrew, the CUtti_---g tool 6 presses down on the embryo which, moved with the microscope stage, shifts under the tip of the cutting tool 6 carrying out the bisection.

The micromanipulator for embryo bisection is prImarily intended for the needs of working groups at animal breeding fIrms transferring cattle embryos. In addition to this, it can be used in experimental laboratories for the bisection. of early stages of mammalian embryos of other specles of farm and test animals, from bicellular stage to the blastocystu stage.

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Claims (4)

CLAIMS I.

1. A micromanipulator for embryo bisection comprising an adjusting mechanism having a first and a-second arm, the first arm being provided with means for its attachment to the objective of a microscope, the second arm carrying a cutting tool, means being provided for the dLsplacement of the arms relative to each other.

2. A micromanipulator according to Claim 1 wherein the second arm is provided with means for the adjustment of the cutting tool.

3. A micromanipulator according to Claim 1 or 2, constructed, arranged and adapted to operate substantially as herein desc-ribed with reference to, and as shown in, the accompanying drawings.

4. A method of embryo bisection by means of a micromanipulator according to Claim 1, 2 or 3, substantially as herein described with reference to the accompanying drawings.

Published 1988 at The Patent Office, State liouse. 66'71 High Holborn, London WClR 4TP. Further copies may be obtained from The Patent Office. Salles Br&nch, St MarT Cray Orpington Nxent BR5 3RD Printed by Multiplex techruques Itd. St Mary Cra.y. Kent Con 1!87 1