Perhaps it's the fact that many procedures in molecular biology are seemingly persnickety: the wrong pH, the wrong temperature, the wrong way of agitating a solution can throw an experiment completely off and can take a scientist ages to figure out what went wrong. Mol Bio is something like Potions, in Harry Potter: if you stir a pot 5 times clockwise, instead of anti-clockwise, under a half moon, instead of a full moon, you are bound to turn yourself into a frog.
Experimental molecular biologists spend ages optimizing protocols and are notoriously conservative about change: nobody follows "if it works, don't fix it" as a molecular biologist. A protocol might take 8 hours, but a mol biologist won't approach a quicker protocol without many mental palpitations, prayers, qualms and shudders. And even after trying the quicker method, he/she may well shrug and say, "My old method was better. It might take me a day and a half of incessant labor, but I think the yield and the quality were better"
Thus, if such a person were to use a premade kit and got beautiful results, well... this person will be unlikely to use any another product for that purpose.
This is the mentality that companies selling molecular biology products take full advantage of. Check out Qiagen's whole genome amplification kit: they have one for genomic DNA, one for frozen tissue and one for single cells; each one more expensive than the previous. But the underlying principle of amplification is exactly the same.
When you check out their protocol for each of these kits, the components are named different in order to make a consumer feel like they are paying (an arm and a leg) for something secretive and magic that will instantly provide them with the answers they seek.
For example, take Table 5 of the Repli-G Single Cell Handbook "Preparation of the master mix"
Component:
H2O sc
Repli-g sc Reaction Buffer
Repli-g sc DNA Polymerase
Now take Table 3 of the Repli-G MiniMidi Handbook "Preparation of the master mix"
Component:
Nuclease free water
Repli-g Mini Reaction Buffer
Repli-g Mini DNA Polymerase.
They are exactly the same components, being marketed under different names. But can you use the Repli-g Mini kit (cost for 25 reactions $199) for a single cell amplification, instead of the Single Cell kit (cost for 24 reactions $488) ? No! Because they have tested the Single Cell kit on single cells and they know that it works. If you were to use the cheaper kit, for this application for which it is not suited, they cannot guarantee that you would get consistent and reliable results.
The hapless lab tech/ grad student/ postdoc convinces the PI that the money must be spent, and the expensive kit is bought, which probably works beautifully and now, this person will continue to buy the more expensive kit and will never try out the cheaper kit because of the suggestion that it might not work.
Shoot. Gotta stop before I am ready. And when I come back, I'd have forgotten the original point of this post....
