up until this point in my research, i’ve used the bacteriophage T4. You guys know it. it’s the classic virus everyone learns about, the first time they learn about viruses. well, T4 infects it’s host, E. coli, at the cell surface, through attachment to surface receptors. now the traditional method of counting the concentration of virus you have in a sample, since they are way too small to be seen using a standard light microscope, is to use a plaque assay. this involves combining your sample with the host bacteria, pouring it onto a nutrient agar plate then incubating overnight. the next day you can count clearings in the bacterial growth (plaques) and use that number to determine your concentration, or titre.
a few weeks ago, i purchased some MS2 bacteriphage to repeat the work i have done with T4, using a different virus. thing about MS2 is tha, unlike T4 which can affect a few different strains of E. coli, MS2 is particularily picky about it’s host strain. this is because instead of infecting it’s host at the cell surface, it instead attaches to hair-like extensions of the bacterium called pili, injecting their genetic material into there rather than directly into the cytoplasm. here’s a neat em picture where you can see the pili and apparently, MS2 attached, in the little square blow-up thing in the bottom right corner.
now my problem is that after buying both phage and host from ATCC (supplier of all things biology-y) i’ll be damned if i can get plaques. i’ve done it 3 times; made all the special media; followed all the instructions: nothing. i am incredibly frustrated. while wirting this, i thought that maybe MS2 can carryout a lysogenic lifestyle, which might explain it. i’ll have to do more research…
aside from that, i was just surfing some science pages and found this story about the finding of earth-like landmasses on the, hillariously titled, Xanadu region of Titan. hydrocarbon hail? liquid methane rain? sounds nice. who knows, maybe one day we’ll find some crazy microorganisms there and some master’s student will write a blog about the difficulty he’s having culturing titaneteria.