Question

Task 2. Chlorophyll Concentration Determination All group members participate 1. Pipette 1 ml of gently mixed chloroplast suspension into a clean glass conical centrifuge tube. Make sure the Spectronic 200 spectrophotometer is turned on. Add 9 ml of 90% acetone, cover tightly with stretched parafilm and mix thoroughly. (You should see a white flocculent protein precipitate.) 2. 3. Centrifuge tube for 3 minutes at 4700 rpm to pellet this precipitate. Move 4 ml of this ml of 90% supernatant to a glass round-bottomed spectrophotometer tube, and add 4 acetone. Note this dilution factor! Q8. What is the dilution factor in step3?

What is the dilution factor for step three?

Answer 1

Dilution factor represents the number of times the original sample has been diluted with a solvent or diluent to obtain an appropriate working solution in an assay. Here, it can be clearly noted that initially the sample was diluted by mixing of 1 ml solute with 9ml solvent thus generatin 1/1+9 or 1/10 dilution factor.

Further, this solution was diluted by adding 4 ml of this solution an dadding 4 ml of acetone i.e. 1:1 dilution. Thus, the individual dilution factor for step 3 is 1:1 (containing 50% of solute with 50% of solvent)

The final dilution factor obtained after step 3 will be 1/10*5 or 1/50.