Unformatted text preview: 5. Medium concentration of extract 6. Substrate and indicator dye 7. Concentrated extract (see table 7.1) Add stock solution ot each tube using the corresponding graduated 5 ml pipette or dispensing device. Adjust spectrophotometer to zero absorbance at 500nm Use test tube 1 as the blank for the spectrophotometer Mix tubes 2 and 3 within ten seconds Place mixture in the spectrophotometer and read absorbance at 20 second intervals from start of mixing. Mix contents of tubes 4 and 5 and repeat measurements for two minutes at 20 second intervals Mix contents of tubes 6 and 7 repeat measuring steps...
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- Fall '10
- Biology, Test method, Laboratory glassware, 0.2M phosphate buffer