displaying the absorbance. Never use any abrasive If the absorbance is cleansers, greater than 2.0, soaps, or the display will show brushes on an error message cuvettes. This stating that the can scratch sample is outside them or leave the range of the a instrument. This will contaminating require you to dilute residue. the sample to gain an accurate Disposable reading. plastic cuvettes can Repeat steps 14-15 be used a few with all other times before samples. they become scratched or When you are stained and finished, clean the need to be cuvettes by first discarded. emptying them, Clean these then flushing with carefully and several changes of they will last purified water. for several Next, flush with uses. several changes of Quartz 70-95% ethanol. cuvettes look Finally, dry upside like glass and down on a paper are made to towel before storing have a long in a safe place. life. Treat PART B: DNA ANALYSIS these with BY SCANNING special care because they From the main are very menu, highlight expensive. Acid Tests” They will last “Nucleic and press Enter. many years if used carefully. Select with “DNA Scan 260/230”. Parameters will display; press the softkey labeled Test”. “Run Insert a cuvette filled with the blank
displaying the absorbance. If the absorbance is greater than 2.0, the display will show an error message stating that the sample is outside the range of the instrument. This will require you to dilute the sample to gain an accurate reading. Repeat steps 14-15 with all other samples. When you are finished, clean the cuvettes by first emptying them, then flushing with several changes of purified water. Next, flush with several changes of 70-95% ethanol. Finally, dry upside down on a paper towel before storing in a safe place. PART B: DNA ANALYSIS BY SCANNING From the main menu, highlight “Nucleic Acid Tests” and press Enter. Select “DNA with Scan 260/230”. Parameters will display; press the softkey labeled “Run Test”. Insert a cuvette filled with the blank Never use any abrasive cleansers, soaps, or brushes on cuvettes. This can scratch them or leave a contaminating residue. Disposable plastic cuvettes can be used a few times before they become scratched or stained and need to be discarded. Clean these carefully and they will last for several uses. Quartz cuvettes look like glass and are made to have a long life. Treat these with special care because they are very expensive. They will last many years if used carefully.