TMB test

What is TMB Test

1. Presented by GAURI VIJAY MASKE VOLUNTEER APPLIED FORENSIC RESEARCH SCIENCES Tetramethyl benzidine (TMB) Test For Blood

2. INDEX Introduction What is TMB ?? Principle of TMB Reagents preparation of TMB Procedure of TMB Test Sensitivity of TMB Test Advantages of TMB test Disadvantages of TMB Test Conclusion References

3. The tetramethylbenzidine (TMB) presumptive test for blood is a catalytic test which is based on the peroxidase-like activity of hemoglobin. TMB is derived from tetramethyl derivative of benzidine which is used as a screening test.
It gives a characteristic blue green color on reacting with hemoglobin. INTRODUCTION

4. When heme in the blood reacts with tetramethyl benzidine in the presence of an H 2 O 2 , oxidation of TMB takes place. As a result, blue green coloured product is formed. Principle of TMB

5. Reagents preparation Tetramethylbenzidine (TMB) reagent Weigh out 0.2 grams of TMB. Add to a 50 ml beaker. Measure out 10 ml glacial acetic acid and add to the TMB. Mix thoroughly until the TMB is dissolved. The shelf life of the solution is one week. Hydrogen Peroxide 3% Measure out 10 ml of 30% hydrogen peroxide. Add 90 ml of deionized water. Mix well using a glass rod. May be stored at room temperature or refrigerated. The shelf life of the solution is one year.

6. PROCEDURE Swab suspected blood stain with clean filter paper . Apply 1-2 drops of the TMB reagent. Note any blue-green color change.
If there is no color change, proceed to the next step.
Add 1-2 drops of 3% hydrogen peroxide.
Note any immediate blue-green color change.

7. Blood with the dilution up to 1: 10000 gave an immediate positive reaction. Blood with dilution up to 1:1000,000 gave positive results within 20 seconds Sensitivity of TMB Test

8. About 1:1000,000 blood dilution is of high sensitivity. All reagents are non-carcinogenic. Its easy, economical , and less time consuming. No need for a confirmatory test , if the test result is negative . TMB reagent can be used for up to one week. A dvantages of TMB Test

9. Very little specification. That is why many untrue things result in vegetables and fruits. Corrosive and acidic reagents are used. Disadvantages of TMB Test

10. TMB is quite good as benzidine for the detection of blood. Their findings and comparable results in terms of sensitivity and specificity lead to the emergence of tetramethylbenzidine as their alternative to the benzidine test. Conclusion

11. https://forensicreader.com/tetramethylbenzidine-tmb-test/ https://www.shopevident.com/category/blood-trajectory/tetramethylbenzidine-presumptive-blood-test-kit 2 nd Edition Forensic Biology By Richard Li References

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