Hello, I rely on your help. On February 27th, I prepared a Bradford reactive, left it for the night at room temperature, filtered it out on the next day and made a calibration graphic with egg albumen. An optical density of samples with different protein content constituted from 0.0237 to 0.0933. Ready Bradford reactive kept in the fridge then.
On 7th March I used this reactive for determination of protein content in Chlorella cells. OD constituted values, that were within ones of the calibration graphic.
Yesterday I did the same, but the values didn't differ and constituted 0.8430, something like that for all samples. I checked OD of plain Bradford reactive and it was just the same.
What might be wrong with the reactive? Do I need to prepare a new one? Or recalibrate the old? And what might such problems be connected with? I've never worked with Bradford reactive and I just don't know how to act.
Please, sorry for grammar mistakes, if there're they. I'm not a native English speaker.
Yes, I just wrote "reactive" instead of "reagent" 😖
