reagent

The at-home tests involve swabbing the inside of your nose to collect a sample, mixing the sample with the included reagent, placing drops of the resulting solution on a test strip, then waiting 15 to 30 minutes for the results.

They are identified by their distinctive granules that stain red when treated with an acidic reagent, eosin, which gave them their name.

Prof. Yoshida explains, "We developed a method for synthesizing stable o-bromobenzenethiol equivalents by bromothiolation of aryne intermediates with an appropriate hydrogen sulfide equivalent and an electrophilic brominating reagent, resulting in controlled reactivity at the sulfur atom which prevents subsequent additions with aryne intermediates."

The researchers utilized potassium xanthate instead of hydrogen sulfide, owing to its better reactivity in aryne reactions and pentafluorophenyl bromide as an electrophilic brominating reagent.

It is called Murakami's reagent, which etches away carbon residue and changes the colour of steel in knife making, for example.