Phage Morphology Assay

Creative Biolabs is a leading service provider that focuses on phage therapy. Based on years of experience and advanced platforms, now we can provide novel phage morphology assays for our clients all over the world.

Morphology of Bacteriophages

With the continuous development of electron microscopy technology, the morphology of bacteriophages has been intensively studied. The phage is tadpole-shaped with a faceted head and a straight tail. The head is a biconical hexagon and measures 950 x 650 Å. The capsid is composed of about 2,000 proteins, and the head wraps a linear double-stranded DNA containing more than 75 genes. The tail is a hollow cylinder consisting of a central hollow core. Bacteriophages can be divided into six groups. Among them, groups A, B, C, D, and E are distinguished by the presence or absence of a tail and the shape of the head, while filamentous phages belong to group F.

Plaque Morphology Analysis

Plaques of different morphologies were produced when phages were co-inoculated with susceptible hosts. There are different types of plaque, including clear plaques, turbid plaques, plaques with clear centers and turbid edges, as well as plaques with a halo. Plaque morphology is an irreplaceable part of phage isolation procedures and is important for phage phenotypic measurements, such as adsorption rate, burst size, and lysis time. Currently, several methods have been established for phage plaque morphology analysis.

Fig.1 Morphology of phage.¹

TEM for Phage Morphology Analysis

Transmission electron microscopy (TEM) is a novel microscopy technique for samples less than 100 nm thick. Compared with light microscopes, TEM presents a significantly higher resolution to capture fine detail. TEM has been widely used in different fields, such as virology, cancer, paleontology, nanotechnology, as well as materials science. Bacteriophages are bacteria viruses that are ubiquitous. TEM plays an important role in morphology-based phage classification. For the phages to be tested, a carbon stabilizer-coated 200 mesh copper grid was inserted into an air centrifuge tube and filled with lysate, followed by centrifugation at 20 psi and negative staining with 2‰ phosphotungstic acid. Eventually, each sample can be viewed with a TEM between 12,000x and 80,000x magnification.

Creative Biolabs offers the most advanced and comprehensive phage morphology determination assays today. We work to amplify your success in a highly collaborative manner. If you are interested in our services, please do not hesitate to contact us for detailed information.

Reference:

1. Islam, Md Sharifull, et al. "Characterization of Salmonella phage LPST153 that effectively targets most prevalent Salmonella serovars." Microorganisms 8.7 (2020): 1089. Under Open Access license CC BY 4.0, without modification.