Subtelomeric fraction in idiopathic MR can be detected by all EXCEPT[aiims nov 2011]

1. FISH
2. MALDI
3. Laser Diode Index
4. Array CGH

Common answer seen in MCQ books is Laser Diode Index.But MALDI and Laser Diodes are a part of Mass spectrometry Used to detect Primary Structure of proteins and Oligo nucleotides.But nowhere I could see Laser Diode Index.