Investigate photosynthesis using isolated chloroplasts (the Hill Reaction)

Grind leaves with ice cold sucrose solution in a mortar and pestle strain the liquid into a cooled centrifuge tube and centrifuge for 5 mins at medium speed pour the supernatant into another cooled centrifuge tube and centrifuge for 10 mins at high speed decant and discard the supernatant add ice cold sucrose solution and ice cold pH 7 buffer solution to the left over sediment and mix gently pour equal volumes of the mixture into test tubes A, B and C, also add the same volume of DCPIP to test tube D only boil tube C over a Bunsen burner then cool it under a tap add some DCPIP to test tubes A, B and C leave tubes A, C and D under a lamp and place B in a cupboard observe until all the colour in tube A has disappeared