List the procedural steps, from start to finish, that are required to prepare indigo from nitrobenzaldehyde and acetone in base, and then test its ability as a dye.
1) Mix 2-nitrobenzaldehyde and acetone in a test tube, then slowly add sodium hydroxyde
2) Collect the purple precipitate by filtration and wash with water followed by ethanol
3) Fit a slit pipette bulb over the side arm of a filter flask
4) Place solid indigo into pre-prepared filter flask and heat vigorously with sodium hydroxide solution in the stoppered flask
5) Add sodium dithionate until the hot solution is a clear yellow
6) Place a fabric strip into the hot solution and heat for 10 minutes
7) Remove the strip, rinse with water, and record the color when dry