I use 10% sucrose solution to feed lab mosquitoes. Until now, I mix sucrose in autoclaved water and use it directly for feeding mosquitoes. Is it necessary to autoclave the sucrose solution itself before use?

  • $\begingroup$ aren't there are standard protocols for feeding these lab animals? or some sort of International Mosquito Research Association $\endgroup$ – aaaaa says reinstate Monica Aug 29 '17 at 5:28
  • $\begingroup$ I tried my best, but couldn't find any standard protocol. They have just mentioned what percentage of sucrose solution must be used. There is no information about autoclaving or filtering sucrose before use. $\endgroup$ – RKK Aug 29 '17 at 5:32
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    $\begingroup$ Sugars usually get charred when autoclaved or at very high temperatures. Autoclaving sugars is unadvisable. $\endgroup$ – user3452673 Aug 29 '17 at 5:34
  • $\begingroup$ instead what you can do is add the sugar after autoclaving the remaining components, in a hood. $\endgroup$ – user3452673 Aug 29 '17 at 5:35
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    $\begingroup$ If the sucrose is to be used as a food source for mosquitoes do either of the possible problems – charring or fungal contamination – actually matter? Also see my contribution to the charring debate in my comment on the answer from Karthik. $\endgroup$ – Alan Boyd Aug 29 '17 at 10:07

I wouldn't autoclave this solution - sucrose will partly break down into glucose and fructose. A portion of the sugars will also caramellize and color the solution yellow to brown.

If you need the solution to be sterile, I would filter sterilize it, although this can be hard because of the higher viscosity of the sugar solution. If you haven't seen any negative effects of preparing the solution fresh with autoclaved water, I don't think there is any need to change your protocol.

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    $\begingroup$ I routinely autoclave 20% sucrose and don't see any evidence of caramellization. Also, 10% sucrose would not be difficult to filter. $\endgroup$ – canadianer Aug 29 '17 at 5:46
  • $\begingroup$ @canadianer I stopped it, after we got brown solutions back. Seems to depend on the autoclave. Our solution was to make really high concentrated solutions (and these are hard to filter), to have the osmotic pressure on our side against contaminations. Works pretty well. $\endgroup$ – Chris Aug 29 '17 at 7:06

I found a standard protocol for the same here : http://vosshall.rockefeller.edu/assets/file/Vosshall%20Lab%20Mosquito%20Rearing%20SOP%20DEC%2012-2014.pdf

Take a look at page no.8. They suggest to autoclave the sucrose solution.

  • $\begingroup$ The protocol refers to a preprogrammed cycle and doesn't specify psi. I vaguely recall using a lower psi setting for sugar solutions – 6 psi/110°C? – as compared to standard 15psi/121°C so maybe that is what this refers to. $\endgroup$ – Alan Boyd Aug 29 '17 at 10:03

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