Troubleshooting the Grocott Methenamine Silver (GMS) Stain

Are you having problems with the GMS stain?

• impure water (tap, other)?

• dirty glassware or uncleaned slides?

• a concentration of chromic acid that is too low (from repeated reuse) or too high?

• lower quality silver nitrate?

• methenamine that has deteriorated?

• refrigerated reagents that have not been allowed to reach room temperature before use?

• an uneven temperature during the incubation step?

• a dilute sodium thiosulfate solution or none at all?

• too much or too little counterstain?

• a gold chloride solution that has deteriorated (due to repeated reuse)?

• fingers or metal forceps to handle slides during staining?

• a silver solution without borate added?

• staining times that too long or too short?