The Adenovirus Reference Material (ARM) was developed under the guidance of the Adenovirus Reference Material Working Group (ARMWG) and the U.S. Food and Drug Administration (FDA), and was made possible through the donation of services and supplies by a large number of laboratories and institutions from the United States, Canada, France, The Netherlands, Germany, and the United Kingdom. The purpose of the ARM is to provide a reference material for use in validating assays and internal standards for adenoviral particle concentration and infectious titer. The NIH Recombinant DNA Advisory Committee recommended the development of such a reference-testing agent in their report issued January 2002. The ARM consists of purified wild type 5 Adenovirus as described by ATCC’s catalog number VR-5…
Category: <span>Viral Reference Materials</span>
The Adenovirus Reference Material (ARM) is a purified and well-characterized wild type adenovirus (Ad5) now available to researchers worldwide. Due to the need for a common reference material, the ARM was produced with the purpose of validating assay methods and internal standards for use in developing recombinant adenovirus for gene therapy. Analysis of ARM by RP-HPLC, however, detected the presence of a contaminant peak with a distinctive A240 local wavelength maximum. The contaminant was found in all of the vials, with some variability in amount between vials. It appears that the contaminant is not associated with the virus and it is unlikely that it will interfere with the use of the ARM as a reference material. The source of the contaminant was probably a leachate or plasticizer from the tubing or containers used during the final processing step…
A Short-Term Field Use and Shipping Stability Study of a Wild Type Ad5 Adenoviral Reference Material
Adenoviral vectors for gene delivery are being tested in the clinic for a number of indications and therapeutic uses. In order to facilitate the comparison of studies from different laboratories, the Adenovirus Reference Material Working Group (ARMWG) has developed a reference testing reagent, which will be referred to as the Wild Type Ad5 Adenoviral Reference Material (ARM). This ARM will allow laboratories to standardize in-house controls employed in assays for the determination of particle concentration and infectious titer of their own adenoviral preparations. As part of this project, short-term field use and shipping studies were performed on the ARM. The virus was found to be stable under simulated shipping conditions, for one thaw after shipping, and at 4 °C for up to four hours after thawing. However, there was evidence of aggregation in some vials with repeated freeze-thaw cycles. Therefore, we recommend that each vial be treated as a single-use aliquot, and that it be used within four hours of thawing…
Recombinant adeno-associated viral (rAAV) vectors are known to be efficient vehicles for gene transfer in animal models. The attractive feature of this vector system consists primarily of long-term gene expression with little or no associated toxicities following administration to a variety of tissues. Previous and ongoing clinical trials in humans demonstrate a very good overall safety profile, but problems persist due to the lack of any systematic method for normalizing doses administered to animals and humans. To date, most of the work involves AAV serotype 2 vectors, but vector systems based on other AAV serotypes continue to develop rapidly. Administered doses are usually based on titer, but the defective nature of AAV makes determining vector infectious units difficult. Titering methods based on vector genomes (using hybridization, real-time PCR, or spectrophotometry) are more reliable, but give no information as to the infectivity of the vector. Determining infectious titer is critical, as the ratio of infectious virions to vector genome-containing virions helps to determine the dose, potency, and strength of the vector preparation…
The development of reference testing reagents has been used successfully in the past to standardize measurements among laboratories, particularly for biological products such as recombinant cytokines. This approach was recommended by many parties with a stake in adenovirus vector delivery in order to address the fact that particle units and infectious units are not standardized in the field. This has made interpretation of preclinical and clinical data, as it relates to the amount of adenovirus vector administered, difficult to compare across the field. An Adenovirus Reference Material is being developed to define the particle unit and infectious unit for adenovirus gene vectors, and create a commonality for comparisons, especially for data related to vector safety…