Select one or two materials and several specimens; experiment to find the best possible process. Standardize your process on these results. Always use the same developer, development time, and temperature for similar processes. Remember, in electron micrography, photographic speed is dependent on development-much more so than with conventional photography.
Select one of the reliable methods of agitation and always use it. Use consistent agitation technique for every film and for each process. This is the key to reproducible results and quality. The best agitation techniques for small laboratories is nitrogen-burst agitation or with intermittent manual agitation in a small tank.
Use fresh processing solutions. Adopt a regular schedule of solution replacement, based on the quantity of materials processed or on the time the solutions have been in use.
Check the label on the photographic material for the proper safelight recommendation - then follow it. Good safelight practice requires using the proper safelight filter, using the correct lamp wattage, keeping the sensitized materials the specified distance from the safelight, and testing the safelight occasionally. Test the safelight by leaving a normally exposed piece of film (half-covered) on the darkroom counter for 30 minutes with the safelight on. Process the film and examine the two halves for any evidence of fogging. Similar densities on both indicate a properly adjusted safelight.
Keep your darkroom and processing area clean. Use dedicated developer and fixer mixing vessels, paddles, and tanks to avoid the possibility of contamination.
Use KODAK PHOTO-FLO solution to help prevent water marks and streaks that may otherwise be produced during drying. This solution decreases the surface tension of water so it flows evenly from the surface of the film without collecting in drops. Mix the KODAK PHOTO-FLO Solution concentrate and the working solution as listed on the product label. Wash negatives thoroughly, bathe them for about 30 seconds in a working solution of KODAK PHOTO-FLO, drain the negatives briefly and hang them to dry. Wiping the negatives is unnecessary. This product is readily available from TEM supplies dealers and professional photographic dealers.