Milk Product Analysis - Biruet Test for Proteins

[@spookz26]

Hello, I did a Biuret test to identify protein concentrations in milk a few months ago, as the experimental part of a scientific paper I need to write for school. I started up using this video to know the exact quantities of milk and reagent that I needed for my experiment; however, my memory is a blur, and I somehow ended up preparing solutions using 100uL of milk, 1mL of distilled water, and 1mL of the reagent. I´ve been scratching my brain looking for academic papers that could make me remember why I ended up using those amounts, but I seriously have no clue. The test actually worked, and the samples turned purple while my non-protein control turned blue, but I needed to get actual numbers regarding the protein concentrations, which is why I ran the tubes through a spectrophotometer. Will my quantities or my usage of distilled water affect my results? I probably used the water to dillute my solution so that the light waves could be read better, but I seriously don´t know if I should´ve done that.

[@ProfessorDrewCollop]

Hi spookz. Thanks for you question. This video was created to get a qualitative analysis (is it there) of proteins in milk. In order to quantify your protein levels, you would need to create a Standard Curve. The issue is, what are you going to use as your Standards for quantitative analysis (how much)? When you do select your Standards, make sure you dilute them exactly the same as your samples.

[@ioannimissailidis9760]

Hey, I'm currently doing this experiment for school. Could you send me your paper? It would really help a lot.

[@ProfessorDrewCollop]

Hi Ioanni. What do you mean "can you send me your paper"? I do not have a publication of results for milk. This was just a protocol I made up for my first years students. The create the video to assist them in performing the assay. Can you please clarify?