Look into smaller fluorescent plate readers for field assessment

[AHuffmyer]

Promega

• $15,000, not an option

Molecular Devices

• About $15,000, not an option

MSE Supplies

• Cost is $4,219.95

Get quotes and look into use of these instruments for field testing

[sr320]

and

**1. IO Rodeo Open Colorimeter Plus -- **

cuvette version

Go to the Open Colorimeter Plus product page and choose:

Sample Type: Cuvette

Price listed: $200. This is the fluorescence-capable version; it is for fluorescence, bioluminescence, or light-scattering measurements, and IO Rodeo says the excitation LEDs and emission filters are customizable but not included.

2. IO Rodeo 570 nm LED board

On the IO Rodeo site, add a:

570 nm LED board

This is the excitation wavelength I'd choose for resorufin. IO Rodeo notes that the Open Colorimeter Plus works with their UV, visible, or IR single-wavelength LED boards.

3. 590 nm long-pass emission filter

Buy:

Edmund Optics 590 nm long-pass filter

The key spec is 590 nm long-pass, because resorufin emission is around 585--590 nm. Edmund lists a 590 nm, 12.7 mm diameter colored-glass replacement long-pass filter.

Important caveat: IO Rodeo examples often use small square filters, such as 6 × 6 mm, placed near the sensor. Their fluorescence blog mentions a 6 × 6 mm long-pass filter and notes that long-pass filters are much cheaper than bandpass filters. So before placing the Edmund order, I would email IO Rodeo and ask:

I am buying the Open Colorimeter Plus cuvette version for resazurin/resorufin. I plan to use a 570 nm LED and 590 nm long-pass emission filter. What physical filter size should I buy for the current cuvette-version Open Colorimeter Plus?

That one email avoids buying a round filter that does not fit neatly.

Expected total before shipping/tax: about $265--310.

Exact sequence

1. Go to IO Rodeo's Open Colorimeter Plus page.
2. Select Cuvette as the sample type.
3. Add 1 to cart.
4. Search IO Rodeo for 570 nm LED board and add 1 to cart.
5. Email IO Rodeo to confirm the emission-filter size for the cuvette version.
6. Order a 590 nm long-pass filter in the size they recommend.
7. Buy standard 10 mm disposable cuvettes.
8. When it arrives, configure as:
   570 nm excitation LED → sample cuvette → 590 nm long-pass emission filter → sensor.

[AHuffmyer]

For IO Rodeo there is also a 527 nm board which is closer to the excitation we use in the resazurin protocol (530 nm)

[AHuffmyer]

Still waiting to get more information from Rodeo IO and MSE supplies - the other options are too expensive.

[AHuffmyer]

MSE supplies could work - Cost is $4,219.95

In communications with Rodeo IO