Anyone know anything about biuret reagent?

[yankeesfan]

The solution turned light pink at first, but eventually turned brown. Protein present or not?

 

[inspiron8200guy]

If I remember correctly, it should start out as a blue color. If there is protien present in the form of amino acids, it will turn color. Brown means that you have a lot of protien. What are toy testing? I had to do an experiment recently on this and that is the only reason I know this.

 

[yankeesfan]

Thanks, that's what I thought. It said that if there was a protein present, it would turn purple, but we were testing what should have been pure protein. So, maybe it was just dark purple.