In the build chamber you build and upgrade your players.

You build a new player by injecting your collected DNA strands into an empty robot from your squad.

You must add minimum 4 DNA strands to build a player, but it is recommended to fill all 8 slots.

If you build a player with less than 8 DNA strands you can always upgrade the player later one by injecting extra DNA into the player.

The better the DNA is (the higher rarity it has) the better the player will also become.