Questions and Answers about Embryo Transfer Products

A. The only difference is the location of the internal backstop that the cotton-plug end of the straw rests against.  When inserted into the gun, approximately 2-3mm of straw must extend beyond the open end of the gun, in order for the open end of the straw to engage and seal properly into the steel tip of the blue sheath. The deep chamber rod is designed for the full length (non-shortened) 132mm x 0.25cc straw, like what is used for fresh transfers or straws sealed with a plastic plug.  Straws that are sealed prior to freezing with a heat sealer or with PVC powder must then be clipped / shortened post thaw and require the F17A shallow chamber rod.  

A. Each is a proprietary line of embryo collection / freezing media. BioLife is made specifically for Agtech and Vigro products are made for Bioniche.  Each line has been sold commercially for many years.

 A.  If you entered the bag each time with a new sterile needle, then the contents can be refrigerated (not frozen) and used again for up to a week.  If the solution is clear and has been refrigerated, most likely it is fine to use. Always check for precipitate or particles coming out of media suspension. If in doubt, toss it out! 

Q.  I am having a problem with embryo straws exploding upon thaw. The cotton plug, or plastic plug blows out as soon as the straw hits the warm water bath.
What could be causing this?

            A. This is due to nitrogen seeping into the straw around or through the wick/powder during freezing.  The nitrogen then expands rapidly during thaw causing either the plastic or cotton plug to blow, much like a bullet out of a rifle.  There can potentially be several causes of this problem:

1)      Too much fluid has been pulled through the plug, and the outer cotton plug is extremely saturated with fluid during freezing.

2)      Not enough fluid has been pulled through the plug and the PVC is not properly wetted or seated.

3)      Straws have been improperly stored in a humid environment causing degradation / partial wetting of the PVC portion of the plug prior to actual straw use.

 What can I do to stop my straws from exploding?

1)      Practice and refine your plug wetting technique.  Make sure you are completely wetting the PVC portion of the plug and stopping immediately after the entire PVC portion is noticeably wetted.  Be sure you’re not pulling too much fluid through and saturating the outside cotton plug as well.  Freeze these straws as you normally would and store them in nitrogen for a week or two.  Make detailed notes and identify what your technique is on each batch.  Thaw the straws and record your results.

2)      Properly store your straws in a dark, dry place.  Preferably in a zip-lock bag, or heat sealed bag.

3)      Straws such as Agtech item# F03 or DT6300 are also believed to be less prone to exploding by some ET practitioners.  Our experience has shown that all straws will function properly if the correct sealing technique and straw storage is consistently exercised.

Embryo Transfer Tips and Advice

·         If you’re not ready to upgrade all the way to aTLS-2200 labeling system, you can start by just using the PTL-19-427 labels. The labels lay flat and make a great surface for writing on with a Sharpie marker.  Then simply peel off the label and wrap it around your straw.  To some, this is much easier than trying to write on the straw or plug sidewall!

 ·         To avoid spilling the contents of your flush filter, be certain the outflow clamp below the EmCon filter or Zona filter is open before allowing medium to flow toward the device.  Otherwise, pressure will build inside the filter and pop the lid off.

  ·         When flushing large, deep-bodied cattle, it is helpful to elevate the front of the cow by 8-10 inches. Build an incline that her front feet walk up onto.  If flushing in a tie-stall barn with a gutter, position the donor so that her back feet stand in the gutter.

 ·         If your search yields significantly less embryos than what you expected from ovarian palpation, get the donor back in and reflush.  It’s a win-win tactic.  If the reflush yields embryos this indicates that the original flush procedure was inadequate.  If no additional embryos are collected from the second flush, this most likely indicates that the ovulated oocytes/embryos were retained in the oviducts and are not accessible by our nonsurgical flush technique.