This conversion involves four steps: (1) temporarily removing the stopped-flow unit in order to remove the beam splitter and open the rear extra port in the sample chamber; (2) moving the light source from the light port of the RSM to the rear extra port of the sample chamber; (3) moving the sample PMT from the stopped-flow unit to the light port of the RSM.
Locate the six screws which must be removed to allow the removal of the stopped-flow unit from the sample chamber. Threw screws are located on the front side of the mounting plate of the unit and the other three are in corresponding positions on the back side of the unit.
Remove the two screws at the 'trigger' end of the stopped-flow unit using the 5/32 T-bar provided in the Olis tool kit.
Remove the four screws at the 'syringe' end of the stopped-flow unit using the 3/32 Allen wrench provided in the Olis tool kit.
Grasp and carefully lift the stopped-flow unit straight up.
Gently place the stopped-flow unit aside. (Suggestion: the unit fits neatly on top of the electronics box).
Locate the beam splitter and the light plug inside the sample chamber.
Loosen (but do not remove) the white nylon thumbscrew holding the beam splitter in place, then remove beam splitter by sliding it out of the collar. Put the beam splitter in its plastic storage bag for safe keeping.
Loosen (but do not remove) the white thumbscrew holding the light plug.
Remove the light plug.
Insert an optical filter of your choice into the excitation lamp filter holder and gently tighten the white thumbscrew in the filter holder to hold the filter in place.
Insert the excitation lamp filter holder into the port from which you removed the light plug. Be sure to position the filter holder so that its white thumbscrew is at 9:00. Then tighten the white port thumbscrew to hold the excitation lamp filter holder in place.
Replace the stopped-flow unit on the sample chamber, ensuring that the unit is seated correctly and is flush with the sample chamber. Replace the six screws removed in step #1, turn each screw just enough that the screw engages but do not tighten any of the screws until all six screws are engaged and you are sure that the stopped-flow is seated correctly. Tightening any one screw before all six screws are engaged may cause binding of subsequent screws and you will have to remove all six screws and start over.
The next procedure is the transfer of the lamp. First, remove the high voltage lamp connections. Note that the red wire goes to the positive connection and the black wire goes to the negative connection; it is critical that you reconnect the wires correctly to avoid destroying the lamp.
Disconnect the nitrogen tube from the lamp housing by squeezing the connection so that the red lip retracts and releases the tube.
Loosen the thumbscrew on the telescoping light tube.
Grasp one end of the telescoping tube with one hand and the other end of the tube with the other hand. Push the two sections of the tube together, causing the section with the smaller circumference to slide into the section with the larger circumference.
Remove the telescoping tube. Then, remove the section with the smaller circumference by sliding it out of the section with the larger circumference.
You will now replace the small-circumference section of the telescoping light tube you just removed with the fluorescence short tube. Find the end of the fluorescence short tube which has a lip inside; insert the other end of the short tube into the large-circumference section so that the end with the lip faces outwards.
Slide the small-circumference section of the fluorescence short tube into the large-circumference section such that about 3/8" of the fluorescence short tube extends out from the large circumference section. Set the fluorescence light tube aside in a safe place; you will need to move the lamp housing before replacing the light tube.
There are two bolts holding the lamp housing to the optical railing. One has the green ground wire attached. Loosen both bolts. Remove lamp housing from optical railing and set it aside momentarily.
Secure the ground wire to the optical railing by screwing the ground wire screw through the optical railing and into the dome nut provided. This ensures that the power supply is grounded.
Move the power supply igniter into its new position behind the RSM near the optical railing that will hold the lamp during fluorescence measurements.
Before mounting the lamp housing to the fluorescence optical railing, the base of the lamp housing must be modified to fit the fluorescence optical railing. This will involve the addition of a spacer and an adapter plate to the underside of the lamp housing. Turn the lamp housing over and place it on the absorbance optical railing from which you just removed it.
There are 4 screw holes on the underside of the lamp housing and three screw holes on the underside of the spacer (the spacer is narrower than the adapter plate). You will need to place the spacer on the underside of the lamp housing such that the two outside screw holes in the underside of the lamp housing line up with the two outside screw holes in the spacer AND the spacer is oriented according to the instructions on the label on the side of the spacer.
Secure the spacer to the underside of the lamp housing using one of the two 10/32 x 1/2" screws provided. Insert the screw in the outermost hole at the nitrogen tube end of the lamp housing/spacer assembly. Snug the screw while ensuring that the hole on the other end of the spacer is still lined up with the corresponding hole in the other end of the underside of the lamp housing.
Place the adapter plate on top of the spacer such that it is oriented as instructed on the label on the side of the adapter plate.
Insert the other 10/32 x 1/2" screw in the hole in the adapter plate on the nitrogen tube end of the lamp housing/spacer/adapter plate assembly. Insert the 10/32 x 1" screw in the inner most screw hole on the other end of the adapter plate.
Turn the fluorescence lamp assembly you just constructed right side up and place it on the fluorescence optical railing, ensuring that the adapter plate is flush with the optical railing as shown in the inset.
Locate the three screw holes in the adapter plate which are used to attach the fluorescence lamp assembly to the fluorescence optical railing. Two are located on either side at the front of the lamp housing; the other screw hole is centered at the other end of the lamp housing (i.e., the screw holes form a triangular pattern).
Insert a 10/32 x 5/8" screw in each of the three holes; insert screws from the underside of the optical railing and turn each screw just enough that the screws engage but do not tighten any of the screws until all three screws are engaged and you are sure that the fluorescence lamp assembly is seated correctly. Tightening any one screw before all three screws are engaged may cause binding of subsequent screws and you will have to remove all three screws and start over.
Insert the large end of the telescoping fluorescence lamp tube assembly into the lamp housing.
Then slide out the smaller section of the telescoping lamp tube assembly as necessary to fit that end of the tube into the port at the rear of the sample chamber. Slide the smaller section out until it is flush with the edge of the port. Tighten thumbscrew to secure.
Reattach high voltage cables, ensuring that the red cable goes to the positive connection and the black cable goes to the negative connection. Reattach the nitrogen tube by inserting tube while squeezing the red lip into the black housing (see step #14).
Next, you will install an adapter at the lamp port of the RSM that will allow you to install the sample PMT at that port. First, back out the three screws in the adapter till the ends of the screws are flush with the inside rim of the adapter.
Slide the adapter onto the lamp port of the RSM.
Tighten the three metal thumbscrews.
Loosen the white nylon thumbscrew on the collar of the sample PMT, which is located underneath the stopped-flow unit.
Gently slide the sample PMT out of the port. Insert a light plug in the empty port and secure it in place by tightening the white nylon thumbscrew.
Remove the O-ring from the sample PMT and insert it into the end of the PMT adapter at the RSM lamp port.
Insert the sample PMT into the adapter and gently slide the PMT in until it stops. Tighten the white nylon thumbscrew on the adapter to secure the PMT.
Enter the RSM-1000 program and go to the Parameter Setup menu. Press "D" to highlight "Single Beam Mode."
To return the RSM to absorbance mode, you will reverse the steps for "Conversion from Absorbance to Fluorescence" with three modifications.
Set the lamp housing on the RSM optical railing and slightly screw in the two screws that hold the lamp housing to the optical railing; just screw them in until they engage. Then, reattach the high voltage cables (red to positive, black to negative), turn on the lamp and stand behind the lamp so you can see the light shining on the entrance slit of the RSM. While watching the image of the light beam shining on the entrance slit, adjust the position of the lamp housing on the optical railing such that the image of the light beam is focused in the center of the entrance slit. The light beam must be focused at the center of the entrance slit to maximize the light throughput. Once the beam is centered, tighten the two screws and complete the conversion process.
