Monthly Archives: November 2014


November 21, 2014

We lost power to most of our equipment. OPP is here already, but we don’t know what needs to be done and whether we will be able to use our 220V power today. Orbi and MALDI-TOF are down.

Thanks to Bob Mills, we are back online. For now.

The AC has been down since this morning when we lost power, and the temperature in the lab is above 26C, so the Orbi’s LC system is down.


November 13, 2014

Orbi is running Yuanjun’s samples. The queue is approximately 40 hours including gel bands that I am currently preparing for analysis.

MALDI TOF has no queue.


November 7, 2014

Orbi is working, the queue is approximately 130 hours.

MALDI-TOF will be in operating condition this afternoon.


November 6, 2014

Orbi is warming up for calibration. Doug will get his data today, Gaozhong’s data will be revisited this afternoon.

MALDI-TOF might get looked at by an engineer who happened to be in the area. I’ll keep you posted!

ETA: MALDI is feeling better, should be up and running by tomorrow.

Isobaric ions

Two (or more) ions are isobaric if they have the same nominal mass but different exact mass. For example positive radical ions of N2, CO, and C2H4 all have nominal mass of 28 units (z = 1). However, their exact (monoisotopic) masses are 28.00559, 27.99436, and 28.03075 units respectively.

TMT reagents are called isobaric tags, which can be confusing. These labeling reagents within each set (e.g. 2-plex or 6-plex) have the same nominal mass and the same exact mass, therefore they are not isobars as defined by IUPAC.


November 5, 2014

Orbi is running Sung-Hoon’s and Doug’s samples; data should be ready tomorrow.

No news about MALDI-TOF as of 2 PM, but a replacement part has been delivered today. This is a good sign.


November 4, 2014

Orbi is running Marcia’s samples. Anna, Matt, Yunxue, and Siva will get their data today. Next in the queue: Sung-Hoon, Doug, and Eric.

No news about the MALDI-TOF.


November 3, 2014

Orbi finally got a new nano-LC column and is running samples again.

MALDI TOF is down for an unknown time. A service request has been placed.