pill testers going bad??? need help please

[phat pants]

does anybody know if the marquis test can go bad and what are the signs of it???

heres the situation: my buddy tested a pill with a marquis test, it turned a brownish shade with a green on the sides to it...i retested the same pill with my marquis test and it went black but with a very slight green on the sides.

does this mean my friend's tester went bad??? and does the slight green edges of the area mean that there is 2cb present in it???

 

[Soma]

Yes they can turn 'bad'. They do lose their effects over time, this can be slowed somewhat by careful storage.

The green tinge around the outside is normal, its the reagent reacting with air, dust whatever. Left overnight the whole solution will turn a murky green