Optimization of tubing method of biopsy samples during preimplantation genetic testing

Background. Preimplantation genetic testing (PGT) is a powerful tool for patients with a high risk of transmitting a genetic abnormality to their children. Unlike other assisted reproductive technologies (ART), it has technical issues which remain unresolved. Objectives. To develop a modified tubing method for placing biopsied samples into amplification tubes for PGT. Material and methods. A modified tubing method was developed and applied to PGT, with the micromanipulator aiding in the fine movement of transfer pipettes, and with a microinjector to minimize the amount of medium which is transferred with the biopsy samples into the amplification tube. A total of 826 blastocysts from 222 PGT cycles performed between December 2016 and December 2019 were retrospectively analyzed. As the tubing of the cells could not always be inspected visually and they would only be detected by the presence of DNA after amplification, the main outcome measure was the amplification success rate. Results. The amplification success rate with the modified tubing method was 99.6%. Conclusions. The modified tubing method is efficient and simple. It is a promising technique for PGT tubing. To the best of our knowledge, this is the first report on the use of a modified micromanipulator and microinjector for improving the tubing rate in PGT cycles, and the presented method is by far the closest to actual use for PGT tubing.