experimental design

Control Samples: 3 Terrifying Tales for Scientists

Posted on by Michele Arduengo
Lab science cartoon
Carl may not scare her…but did she remember the controls?

Warning: This blog contains stories about phantom serial killers, frankenfoods, mysteriously phosphorylated bands and unrequited ligations that may be disturbing to some people. Children or scientists prone to anxiety over irreproducible results should read this with their eyes shut.

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Clouds hung low in the sky, and the late October wind howled between the buildings, rattling the window panes of the basement laboratory. The grackles cawed in desperate warning, their flocks changing the evening color palette from gray to black. I was as unsettled as the weather, watching my blot slosh back and forth.

Continue reading “Control Samples: 3 Terrifying Tales for Scientists”

Recommendations for Normalizing Reporter Assays

Posted on by Anupama Gopalakrishnan

Reporter assays can be used to investigate a variety of questions from cell signaling to transcription. Your controls depend upon the question you are trying to answer.
As a technical services scientist, I get to hear about many amazing experiments at the planning stage, and I often talk to researchers about how to plan a reporter assay. For the uninitiated, reporter assays are used to “report” the ability or the efficacy of the inserted DNA element to induce/ regulate gene expression as a qualitative or quantitative measure. A typical experimental protocol involves cloning of a DNA fragment upstream of a reporter gene in a plasmid, (and of course confirming the clone by sequencing), transfecting a mammalian cell line with the plasmid and assaying for reporter gene expression by measuring fluorescence, luminescence or absorbance signals. A positive signal would indicate that the cloned DNA element is responsible for driving the gene expression of the reporter.

As in any biological experiment, the controls are as important, if not more, than the actual samples. There are multiple options, and researcher needs to choose the controls depending on the question they would like to ask. Continue reading “Recommendations for Normalizing Reporter Assays”