ClonaCell™-HY Medium D is a semi-solid methylcellulose-based medium containing serum and the selective agents hypoxanthine, aminopterin, and thymidine (HAT). This medium is used after fusion of lymphocytes and myeloma cells to select and clone hybridomas in one step. Individual parental hybridoma clones and their progeny remain localized together in the semi-solid matrix as they grow to form distinct colonies. This prevents the loss of rare clones by overgrowth from faster-growing cells, as can occur during selection in a liquid medium, and facilitates the isolation of monoclonal colonies. The hybridoma colonies can be easily picked from the semi-solid medium by manual or robotic methods and dispersed into a liquid medium for screening and expansion. This medium has been verified for use in mouse and rat hybridoma development and reportedly is compatible for production and cloning of hybridomas using lymphocytes from a variety of host animals including human, mouse, rat, and hamster.

Benefits of semi-solid cloning:
• Individual cells are suspended in viscous medium and form physically separated, discrete colonies that are easily isolated.
• Monoclonal cell lines are isolated in less time using fewer resources compared with selection and cloning by limiting dilution.
• Diverse clones with a wide range of growth rates and productivities form discrete colonies in the viscous medium. As a result, rare and high-producing clones can be individually isolated more easily using simultaneous selection and cloning in semi-solid medium compared with selection in bulk liquid cultures.