Capsule-Based Negative Staining of Virus Samples on TEM Grids: A Heavy Metal Staining Technique to Visualize the Ultrastructure of Enveloped Viruses

To begin, mix the virus suspension with an equal volume of 4% Glutaraldehyde to achieve a final concentration of 2% Glutaraldehyde. Using fixative, inactivate the virus for at least 24 hours. Decontaminate the tube, and transfer it to the BSL2-EM facility.

After this, attach a grid-loaded capture to a pipette. Aspirate the mixture into the capsule. Place the pipette on its side with the grids oriented horizontally for 10 minutes.

Next, pick up the pipette, and expel the virus mixture into a waste container. Aspirate 40 microliters of deionized water into the capsule, and then, dispose of the water in a waste container. Repeat this wash three times.

After this, aspirate 40 microliters of either 1% UA or 1% PTA into the capsule for 30 seconds. Remove the capsule from the pipette. Using filter paper, blot-dry the grids, then, allow the grids to air-dry.