Development of 5-(4,6-dichlorotriazinyl) aminofluorescein (DTAF) staining for the characterisation of low acyl gellan microstructures

Although hydrocolloids are used in a wide range of applications, understanding of microstructural interactions in the past have often based solely on mechanical properties. Systems which contain multiple polymers of similar properties are often, therefore, hard to fully understand since it is difficult to distinguish visually between the different phases. As such, the development of a novel staining method could aid our understanding of how microstructure relates to mechanical properties.

This research has developed a method for the staining, and consequent visualisation, of low acyl gellan gum using 5-(4,6-dichlorotriazinyl) aminofluorescein (DTAF) without staining of a second polymer (gellan or PVA).

The addition of DTAF on the gellan backbone was shown to affect mechanical properties, resulting in stronger gels. The influence of changing the ratios of DTAF stained gellan, and unstained gellan mixtures was also investigated. It was found; however, that these form phase separated networks. In conclusion, DTAF modification does enable fluorescent staining of gellan and allows the visualisation of microstructural interactions; however, since the modification influences the mechanical properties of the material, this staining method would be best employed as a validation method when used alongside other analytical techniques.