7
APPLICATIONS
CROSSLINKING OF DNA/RNA
The Spectrolinker can be used to covalently bind nucleic acids to
membranes after Northern, Southern, slot or dot blotting, and colony or
plaque lifts. Studies [1,2,3] indicate that 120 mJ/cm
2
is an optimal dosage
for attachment of DNA or RNA in any of these procedures to nylon or
nitrocellulose membranes. In order to obtain the best results following the
DNA or RNA transfer step, the membrane should be placed inside the
Spectrolinker chamber after the membrane is dried. Place the membrane with
the side to which the nucleic acids are attached facing upwards (i.e. towards
the light source) so that the nucleic acids are directly irradiated. Select an
energy value or press ‘‘OPTIMAL CROSSLINK’’ followed by ‘‘START’’ to
initiate the desired function.
NICKING DNA
The Spectrolinker can be used to nick the ethidium-bromide-stained DNA in
agarose gels in place of a depurination wash [4].
GENE MAPPING
The Spectrolinker can be used to create thymine dimers prior to treatment
with a restriction enzyme. The formation of dimers at or near the recognition
site inhibits cleavage [5].
4. Time Mode —
When this mode is selected, the SECONDS LED lights to
indicate that the value displayed or to be entered represents seconds.
Enter the exposure time desired to a maximum of 9,999 seconds (2 hours,
46 minutes and 39 seconds). The minimum value that can be entered is
one second.
The desired time should be entered on the number pad after the ‘‘TIME’’
pad is pressed. Press ‘‘START’’ to begin operation. After the time has
expired, the Spectrolinker beeps four times and the display flashes ‘‘END.’’
Open the door at this point and the display will oscillate between ‘‘DOOR’’
and ‘‘0.’’
If you want to repeat the previous operation, just close the door and press
‘‘START.’’ The Spectrolinker remains in the TIME mode and displays the
last time entered.
To alter a previously entered time, press ‘‘RESET,’’ enter the new value
and then press ‘‘START’’ to begin the operation.
When the chamber door is opened during an operation, the display will
oscillate between ‘‘DOOR’’ and the time remaining. To resume the
operation, close the door and press ‘‘START.’’ Otherwise, press ‘‘RESET’’
to return to the WAKE state.
