Transformation Review

REVIEW OF TRANSFORMATION OF PNEOMOCCAL TYPES - STUDY CONDUCTED BY AVERY, MACLEOD, AND MCCARTY

By: Beth Bennett

METHODS ANALYSIS

Avery, Macleod, and McCarty confirmed that the material they witnessed that induced transformation in Pneumococcus was DNA and not protein by isolating and extracting the transformation material with alcohol or ether, and subsequently performing a series of tests.

Among submitting the DNA to heating tests and other numerous tests stated below in the SUMMARY section, some of the tests used to identify the material included an Elemental Chemical Analysis that was used to examine the content of Nitrogen, Carbon, Hydrogen, and Phosphorous contained within, and an Enzymatic Analysis, wherein they subjected DNA to the enzymes trypsin, chymotrypsin, and combinations of both.

The transformation material’s reaction was also observed in mediums made from different animals such as, dog intestinal mucosa, rabbit bone phosphatase, swine kidney, normal dog and rabbit serum, and pneumococcus autolysates. These mediums contained enzymes capable, or not capable of degrading DNA.

RESULTS ANALYSIS

In the Elemental Chemical Analysis, the transformation material revealed to contain a ratio of certain elements found in DNA, but not protein – the first step in confirming it was DNA.

In the Enzymatic analysis, the transformation material was subjected to enzymes that can break apart RNA and protein, but not DNA. When witnessing that the enzymes had no effect on the DNA, they confirmed it was not protein or RNA that was the transformation material.

When subjecting the DNA to different animal mediums, it was found that the DNA was degraded only in preparations that contained an enzyme capable of degrading it.

SUMMARY

They first sterilized the material with alcohol, then added a charcoal-absorbed broth to destroy the enzyme that inactivated the transforming principle. It then underwent a series of dilutions before being transferred to a blood culture...