Hematoxylin and Eosin staining of organotypic cultures. The cultures were harvested 14 days after air-lift and embedded for paraffin sections. Primary cultured human keratinocytes were seeded onto the dermal equivalent containing human fibroblasts. The resulting multistratified epithelium obtained had matured fully by day 14. From the protocol by Gangatirkar et al. Cover by Jessica Iannuzzi.

Scanning electron micrograph showing a Chlamydomonas reinhardtii cell before isolation of chloroplasts. From the protocol by Mason et al., describing a rapid method for the isolation of chloroplasts. Cover by Jessica Iannuzzi.

Technique for infiltrating Agrobacterium into tobacco epidermal cells for transient expression of fluorescent fusion proteins. The top of the leaf is supported with a finger while a syringe containing Agrobacterium in infiltration medium is placed over a small needle mark on the lower epidermis. With gentle pressure on the plunger, liquid fills the mesophylar air spaces of the cell. From the protocol by Sparkes et al. Cover by Jessica Iannuzzi.

Head region of a transparent albino Xenopus laevis tadpole, showing the optic tectum. From the protocol by Bestman et al., describing transfer of DNA or macromolecules to Xenopus tadpole brains by single cell electroporation. Cover by Jessica Iannuzzi.

Four-dimensional imaging of convergent-extension movement of neutral plate and organogenesis derived from placodes in the zebrafish embryo. From the protocol by Hatta et al., which describes cell tracking using a photoconvertible fluorescent protein. Cover by Erin Boyle.

Overview of the 12-color image obtained using a human COBRA-FISH probe set. A translocation can be seen that was not detected by conventional cytogenetic testing. From the protocol by Karoly Szuhai and Hans Tanke. Cover by Erin Boyle.