Xanthoproteic's Test - Colour Reaction of Proteins

Overview

Xanthoprotein is a yellow acid substance formed by the action of hot nitric acid on albuminous or protein matter and is changed to a deep orange-yellow colour by the addition of ammonia. The colour reaction is used to identify such proteins in the Xanthoproteic Test.

 

This video lesson demonstrates the laboratory procedure in Xanthoproteic Test. At the end of the lesson, students should be able to write a well-balanced reaction equation, distinguish between amino-acids with a phenyl ring, a phenol or an indole group from other amino acids and describe the test and positive result.

Author(s): George KoffuorView Details of Author
Year: 2012
Keywords: xanthoproteic test, amino acids, phenyl ring, phenol, indole group, amino acids, qualitative test
Licensing Condition:

cc-by-nc© 2012, KNUST

Unless otherwise noted, the content of this programme is licensed under the terms of a Creative Commons Attribution-NonCommercial 3.0 Unported License.

Disclaimer

 

Any information and/or video demonstration in this material is intended to inform and to educate and is not a tool for self-diagnosis or a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. You should speak to your lecturer, healthcare professional or lab technician and make an appointment, if you have questions or concerns about this information.

 

Viewer discretion is advised. The educational material contained herein may contain medical images that non-professional viewers may find disturbing.

 

References herein to any specific commercial products, process, or service by trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favouring by the Department of Pharmacology.

The views and opinions of authors expressed herein do not necessarily state or reflect those of the Department of Pharmacology, and should not be used for advertising or product endorsement purposes.

 

Users should consider the need to obtain any appropriate professional advice relevant to their own particular circumstances.

 

Note: You assume all responsibility for use and potential liability associated with any use of the material. Material contains copyrighted content, used in accordance with Ghanaian law. Copyright holders of content included in this material should contact the authors with any questions, corrections, or clarifications regarding the use of content. The copyright holders for this programme do not license the use of third party content posted to this site unless such a license is specifically granted in connection with particular content. Users of content are responsible for their compliance with applicable law.

 

Introduction

 

Xanthoproteic Test is used to distinguish amino acids with a phenyl ring, a phenol or an indole group from other amino acids.

This reaction is due to the nitration of phenyl rings present in Tyrosine, Phenylaline and trytophan (amino acids) to give Xanthoprotein yellow substituted products. On addition of alkaline to these, a salt changes the colour from yellow to orange.

Objectives

 

Write a well-balanced equation reaction for Xanthoprotiec test

Distinguish between amino-acids with a phenyl ring, a phenol or an indole group from other amino acids

Describe the test and positive result.

 

Lesson Content

 

Xanthoproteic's Test (video)
Xanthoproteic's Test

 

Credits

 

Author

gkoff

Dr. George Koffuor
Department of Pharmacology
College of Health Sciences - KNUST
Kumasi, Ghana

Student Volunteer


Manasseh Amenyedokui
Department of Communication Design
CASS - KNUST
Kumasi, Ghana

 

OER Technical Support

 

 

 

Benjamin Prempeh
OER Media Specialist
KNUST, Kumasi - Ghana
adobrog@yahoo.com

John Kofi Dogbey
Media Specialist
KNUST,Kumasi - Ghana
johndogbey@gmail.com


Voice Over

ella kasanga

Ella Kasanga
Kumasi, Ghana

 

Acknowledgment

 

This programme was produced with support from the following:

acknow-logo