BSS – Bee Semen Solution

01 · WHY HYPEROSMOTIC

The chemistry behind it

Drone semen lives in a medium of high osmolarity. Diluting it in an ordinary physiological solution would draw water into the spermatozoa and damage them, so BSS is formulated hyperosmotic to respect that balance.

It also acts as a buffer: it holds the pH steady through every stage — collection, mixing, transfer and storage — which is exactly where semen is lost if something drifts.

02 · THE COLOUR IS TO SEE THE MIX

And it is not a cosmetic detail

The main job of BSS is to mix the semen of several drones evenly, which is what allows a polyandrous insemination and reproduces what a queen does on her mating flight with ten or more males.

The colouring lets you see at a glance that the mix is uniform, so there is no need to agitate hard to be sure. It is mixed with a gentle spiral movement, avoiding bubbles.

And before you start: wet with BSS every surface that will touch the semen — syringes, capillaries, tools. Without that step, cells are lost to adhesion and to the abrupt change in osmotic pressure.

03 · 1,000 XG IS THE CEILING

If you are going to centrifuge

The mix can be reconcentrated by low-speed centrifugation, and there is a limit worth not crossing: the literature puts the ceiling at 1,000 xg.

Above that figure you can lose up to half the viable spermatozoa. That is why a centrifuge with adjustable speed matters rather than a single-speed one.

04 · ONCE OPEN, USE IT THAT DAY

Where we differ from the maker

Unopened, BSS keeps up to 24 months between 4 and 25 °C. But once the ampoule is open — or antibiotic has been added — that changes.

The maker allows up to two days. Several specialists recommend not reusing it the following day, because sterility is no longer assured, and that is the criterion that strikes us as prudent. That is why it comes in 2 ml ampoules: they are single-dose by design, not a bottle to work through.

05 · IT IS A CONSUMABLE, NOT A KIT

Before adding it to the basket

Instrumental insemination needs an insemination device, a stereomicroscope, CO₂ and training. This solution is one of the consumables used up inside that process.

If you are building the setup from scratch, BSS is not the starting point — it is what you buy once you have the rest and are about to work. Semen washed in BSS is kept between 14 and 17 °C and with the asepsis the whole process demands.

06 · BEFORE YOU BUY

These are 5 ampoules of 2 ml: