Will My Buffered Formal Saline Vials Stay With Me Forever?
Buying vials in bulk is smart, but poorly stored or expired formal saline can damage samples. Here's how to store them and how long they last.
It’s the start of bull buying season and, with a number of bull breeding soundness examination (BBSE) tests lined up in the calendar, you have decided to bulk buy some buffered formal saline (FS) vials from the team here at QSML.
Firstly, well done on being organised! And great choice in selecting QSML vials. Our screw top lids ensure there is no leakage during postage.
But if you don’t properly store your FS vials, you may find that your good organisational skills get you into strife down the track.
The issue with expired vials
We have had two cases of spermiograms with very high distal midpiece reflex (DMR) without droplets and bent tails which, after discussion with the practitioners, may have occurred due to the age and storage of the FS in use. This is unfortunate, as it may require a second visit to the bull to check that the problem is due to the FS and not the bull.
Storing your QSML buffered formal saline vials
Just like the Barth tapes, a hot car is not conducive to a long life for an FS vial.
The initial formalin is made from formaldehyde gas mixed with water and a buffer. This dissolved formaldehyde will readily polymerise to paraformaldehyde, so to prevent this, 10% methanol is added to the formalin. However, this only slows the process down. Eventually polymerisation will still occur, just at a slower rate.
Formic acid also condenses from the formaldehyde, which lowers the pH of the solution over time. pH may particularly affect the sperm midpiece and principal piece. Check your containers of formalin or FS vials for the telltale white precipitate and cloudiness.
We recommend you store your vials in the air-conditioned clinic and take the required amount with you for each collection. The recommended long term storage temperature for formalin is between 15°C and 30°C.
Lifespan of a QSML buffered formal saline vial
QSML vials are designed to last 12 months (with proper storage) from when you order them. If you have vials older than 12 months, we recommend you check them. If they appear cloudy with any precipitate they have expired and you will need to order new ones.
There is nothing worse than being asked to collect a bull and realising you don’t have FS on hand. It may be wise, however, to only purchase sufficient vials annually prior to your main BBSE season.
If you’d like to order vials, you can do so right here.
