Long pass filter set

With wide field fluorescence microscope, examine the cultures for fluorescence with a 488 band pass filter set and with a 546 long pass filter set (explanation in Chapter 13, Microscopy and Images). With the CCD camera configure the software and hardware for capturing the images. 

A complete view of the filter set shows the excitation filer, dichroic, and the emission filter spectra plotted together (Fig. 13.3a). This filter set is called long pass filter set because it will transmit all excitation photons above 550 nm. This long pass filter set allows maximum detection of the 488 emission. 

The main problem has been a methodological one. The patch clamp analysis of single channels views the world of channels through a very small analytical window [10]. A single channel event (opening) needs to be sufficiently long-lived and sufficiently large to be picked up within the current noise band under optimized conditions, and with the low-pass filter set to say 2 kHz. The open time needs to be close to a millisecond and the current amplitude close to 0.5 pA to permit detection. 

The HMBC also incorporates a low-pass filter that tries to reject the one-bond correlations seen in HSQC/HMQC. Low pass means that only the low values of 7ch (0-10 Hz) are allowed to pass through and produce crosspeaks in the 2D spectrum. Because there is no 13 C decoupling, the one-bond correlations appear as wide doublets (7 150 Hz) centered on the XH peak position in F2 (Fig. 11.10—squares). They obscure the weak HMBC crosspeaks and can easily be misinterpreted as long-range correlations, especially if one of the two components of the doublet happens to fall at the position of another peak in the XH spectrum. The low-pass filter is set to reject a particular 7 value, typically 135 Hz for molecules dominated by saturated hydrocarbon (e.g., 3-heptanone, menthol, cholesterol), 142 Hz for sugars, and 170 Hz for molecules dominated by aromatic carbons. The same... 

Long pass fluorescent filter set - transmits all excitation photons above a cutoff wavelength this filter set allows maximum detection of a fluorophore emission. 

On Lab-Tek chamber slides, MCF-7R cells are seeded at 5 x 10 cells per chamber and incubated at 37°C for 24 h in a humidified atmospheric air containing 5% CO2, and the medium is replaced with fresh medium containing 0.3-pM rhodamine 6G with or without 50-pM reserpine, with 100-pg/mL samples in separate chambers of the slide. The cells are incubated at 37°C for another 3h and imaged using fluorescence microscopy with a 510-560-nm band-pass excitation filter and a 590-nm long-pass emission filter set. 

Fig. 10.12. Transmittance of the band pass edge filter sets (a) long-wave pass, and (b) short-wave pass [2347].

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