Preparation of 1% Starch Solution

Purpose:

The purpose of this experiment was to prepare 1% starch solution for long-term storage. The solution is intended to be used as an adhesive for microscope slides (to mount paraffin sections), and as an iodine indicator. 50ml ethanol was added as a preservative (anti-microbial).

Process:

250ml of solution was prepared.

1. 2.5g of cornstarch was weighed and mixed with 50ml of distilled water.

2. 150ml distilled water was boiled separately.

3. 50ml slurry was added to the 150ml of boiling water.

4. Mixture was boiled until it turned translucent/transparent.

5. Mixture was cooled to room temperature.

6. Mixture was filtered.

7. 50ml of ethanol was added.

8. Mixture was filtered.

9. Mixture was transferred into a 250ml volumetric flask and distilled water was added up to the mark, to combat any excessive evaporation of water during boiling.

10. Mixture was left standing overnight.

11. Solution was bottled and stored in a 250ml wash-bottle.

While this protocol - with the repeated filtration and overnight stand - might seem over-the-top and excessive, since the primary purpose of this solution is to serve as an adhesive to bond paraffin sections to microscopy slides, I went the extra mile to ensure that the solution is as lump-free as possible. Even tiny lumps, if present, could show up under the microscope as gigantic blobs which would ruin the final image.