The VSV purified bulk concentrate from the newly developed process also demonstrated higher purity and low residual level compared to purification via sucrose gradient centrifugation. For example, the staining bands of VSV proteins (M, N, P, G and L) from the newly developed process (FIGS. 5A, 5B, lane 9) were more intense than the staining bands of the VSV purified via sucrose gradient centrifugation (FIGS. 5A, 5B, lane 11) (with less intense impurity protein staining bands), indicating a higher quality VSV product was achieved by the novel purification process set forth in FIG. 1. In all four scale-up runs, similar product quality was achieved (data not shown) based on impurity protein profile and intensity of the VSV protein bands.
Size Exclusion-High Performance Liquid Chromatography (SE-HPLC) Analysis. A SE-HPLC analysis for VSV was developed (see, Example 1), which provides a simple and convenient method to separate VSV from impurity proteins and qualitatively analyze the VSV purification process. To protect the column, only clarified samples were injected into the column. The VSV flows out from the column as an elution peak with a retention time of 7.5 minutes (data not shown). The contaminant/impurity protein peaks (which have a longer column retention time) elute from the column after the VSV peak and therefore need to be eliminated/removed from the VSV product. The majority of impurities were removed in Mustang™ Q flow-through and wash, which confirms the results of SDS-PAGE analysis. In the UF/DF step, buffer related impurities were removed and no VSV was lost in any of the permeates (data not shown). Following the final 0.2 μm filtration, the VSV product eluted from the SE-HPLC column as a single major peak with retention time of 7.5 minutes, followed by two smaller peaks corresponding to buffer blank. (data not shown).

### Language ###
English

### Assessment ###
The text mentions a specific retention time for VSV in SE-HPLC analysis, which could be a valuable technical detail to query.

### Query ###
What is the retention time for VSV in size exclusion chromatography?
What is the retention time for VSV in size exclusion chromatography?