Method and Materials:We calibrated the conductivity sensor by measuring the conductivity when distilled water and 1.1% NaCl (338mOsm/kg) is added. We made sure that the conductivity probe correctly attached to the right insert on the SW500 Interface which is connected to the computer.
We took small beaker to the front of the room and we filled it ÃÂ¾ full with the prepared solution. We opened "Lab Group" folder. We then opened "Laboratory 2" folder. We clicked on the sensor. We then opened the calibration section of the program. We placed the conductivity probe first into distilled water and then we pressed "take reading". We inserted the concentration of distilled water in the table as 0mosm.
We opened the program for laboratory 2. We placed the probe in one of the 12 solutions. We started recording by activating the start button. We continued recording until the readings are stable then we clicked the "stop" button.
We used the "smart tool" to read the condutivity value and then we entered the data in the table.
We removed the conductivity sensor from the beaker and then we shaked the sensor off. We made similar measurements of the remaining 12 NaCl solutions, and then we entered the data into the data table in the row labeled conductivity. We saved the data file in our own group data folder. Next, we determined the osmolality of each of the 12 solutionsWe prepared test solutions; we used red grease pencil to label the 12 test tubes from 1 to 11. We marked the last test tube with a letter "C" refers to Control. From the front of the room, we placed 5 ml of 0% NaCl in the control tube. We then placed 5 ml ranging in concentration from 0.1-1.1% NaCl into the other 11 tubes using pipettorWe Used the Eppendorf micropipette provided to add 20 l of blood to the tube. We attached the cap onto each tube and then mixed gently. We placed the circular test tube rack holding the 12 tubes into the provided water bath at 37OC for 30 minutes.
We mixed the tubes gently after incubation and then centrifuge the tubes for 5 minutes at 3000 RPM. We turned on the colorimeter; we next filled one of the cuvettes with distilled water to serve as reference. We pressed the "Select" and "Start/Stop" buttons at the same time. We inserted the reference cuvette and then pressed 'Select'. We waited until it said "CAL done". We then opened the lid and removed the reference cuvette. We pressed 'Start" and began measuringWe transferred the solution gently using pipette from the top of the 'C' into a clean rectangular cuvette so it is filled to within 0.5 cm from the top; we made sure to use a new pipette and a clean cuvette for each test tube measurement . We placed the cuvette into the Colorimeter and closed the lid. We read the %T (% Transmittance) value of the "Control" tube and then recorded the value in the table. We left the Colorimeter running to measure the %T value for cuvettes 1-10. After completing all measurements, we made sure to turn off the Colorimeter.
Bibliography:animal physiology, 2nd eddition, Bulliet and Crossley