CUNY Mass Spectrometry Facility

@ Hunter College

*Small Molecules to Intact Proteins*

Location

    Hunter College North Building
     Room 1315B
     Telephone: (212) 650-3590
     Fax:            (212) 772-5332

Mailing Address

     Dr. Cliff Soll
     Hunter College Chemistry Department
     695 Park Ave.
     New York, NY 10065

Email: cliff.soll@hunter.cuny.edu

Submitting Samples

Samples should be sent to the mailing address at the top of the page. Do not send samples inside of a standard envelope since the mail sorting machine will crush them. Use larger envelopes and wrap the samples with bubble wrap. Please fill out as much information as possible about your sample on our facility form. Make sure that your sample is soluble in the solvent that you specify on the form. The more information that you supply, the better the chance that you have for a successful analysis.

Small Molecule Analysis

Unless otherwise instructed, small molecules will be analyzed by high resolution time-of-flight analysis using electrospray ionization or a combination of electrospray and atmospheric pressure chemical ionization.

Results

Electrospray Positive Ionization: The data may show the molecular weight (M) plus a positive charge from various species present in our solvents. Possible adducts can be:

M+H⁺ (M+1)

M+NH₄⁺ (M+18)

M+Na⁺ (M+23)

Electrospray Negative Ionization: The data may show the molecular weight (M) plus a negative charge from various species present in our solvents. Possible adducts can be:

M-H⁺ (M-1)

M+Cl^- (M+35/37)

M+Formate^- (M+45)

M+TFA^- (M+113)

Intact Protein Analysis

Intact protein analysis is performed on our Agilent 6210 Time-of Flight instrument. Using electrospray ionization which multiply charges the protein of interest, we can obtain MW information of proteins up to the 200kD range.

Keys To Successful Analysis

1. Sample Quantity –

2. Buffer Systems -

Peptide Digest Analysis

We do NOT have the personnel to carryout the digestion of your protein samples. If you perform the digest, we will perform the mass spectral analysis. Analysis can be performed using various methods and choices have to be made as to what type of analysis will be used. Various options are:

1. Instrumentation

A. Time-of-Flight – will provide high resolution peptide mass fingerprint data

B. Ion Trap (MS/MS) – will provide fragmentation and sequence data. Post-Translational modification information can be obtained through the use of both CID and ETD (electron transfer dissociation) fragmentation

2. Ionization Source

A. Electrospray – provides multiple charging of peptides and is generally used when HPLC analysis of the digest is performed.

B. MALDI (Matrix Assisted Laser Desorption) – peptides mixtures are ionized by mixing with a matrix followed by irradiation with a 355nm Nd:YAG laser. This ionization source is at atmospheric pressure. Analysis can be performed where the sample is HPLC’d and then robotically spotted on the MALDI plate when a peptide is detected.

3. HPLC Analysis

A. Chip HPLC Analysis – used for analysis of digests containing very low levels of peptides

B. Capillary HPLC – analysis is usually performed on 0.3 or 0.5mm columns

C. Microbore (1.0mm) Narrow Bore (2.1mm) HPLC – mainly available on the Time-of-Flight instrument

Directions To The Facility (Room 1315B North Building)

The CUNY Mass Spectrometry Facility is located in the North Building of Hunter College. The entrance to the building is on 69th street between Lexington and Park Avenues on the south side of the block. Upon entering the building go to the elevator bank on your right side (they go to the higher floors). Take the elevator to the 13th floor and exit to your left. Go all the way to the end of the hallway. Make a right turn and go about 5 ft and make a left turn. Go straight into the short hallway (grey floor) for about 15ft and you will be at the door to the facility.