A new method of three-dimensional measurement by differential interference contrast microscope

Phase-subtraction cell-counting method for live mouse embryos beyond the eight-cell stage

“…Additional techniques have been developed to reconstruct quantitative phase information from DIC images, but they have not been applied to large biological samples greater than 20 m in diameter. [31][32][33][34][35][36] The diameter of a mouse embryo is approximately 100 m, including the zona pellucida, and the diameter of a human embryo is 22 approximately 130 m.…”

Quantitative phase microscopy through differential interference imaging

“…Methods specifically for reflection DIC have also been developed. 17,18 Recent additions to these contributions include ͑1͒ an iterative phase estimation method developed for reflection DIC, which incorporates the use of an atomic force microscope; 19 ͑2͒ a method applying noniterative deconvolution, with an approximate MTF, to phase-modulated DIC images in the weak phase regime developed for generally shaped phase objects in reflection; 20 and ͑3͒ results from a quantitative method, employing phase-shifting techniques similar to those used in the method discussed here, showing that the Abel transform can be used to numerically integrate linear phase gradients of rotationally symmetric objects with high accuracy. 21,22 Alternative approaches to quantitative phase microscopy that do not rely on DIC microscopy include quantitative phase amplitude microscopy, 23 fast Fourier phase microscopy, 24 phase-dispersion microscopy, 25 spiral phase contrast microscopy, 26 optical coherence microscopy, 27 digital holographic microscopy, 28,29 structured illumination phase microscopy, 30 and scanning transmission microscopy with a position sensitive detector.…”

“…1, the effective transfer function for DIC, with a phase bias of 2 = / 2, is asymmetric about the zero frequency and has a zero value near −0.4 cycles/ m. If the phase gradient of the object being imaged is varying slowly, so that it is approximately constant over a distance equal to the shear distance, the transfer function can be interpreted to predict the strength with which the signal from a particular phase gradient will pass through the imaging system and is sometimes referred to as a phase gradient transfer function. 6,20 Decreasing the shear size will increase the range of phase gradients that can be imaged before a zero occurs, but may also decrease the linearity of the DIC response and vice versa. 6 As a result, equal but opposite phase gradients will not necessarily be imaged with equal signal strength and still may not be suitable for quantitative analysis.…”

Modeling images of phase information for three-dimensional objects

“…[1][2][3][4][5] Many of the phase objects of interest to biologists are optically thick, 6 and are well visualized by techniques such as Difference Interference Contrast (DIC) microscopy with high resolution, but in general this technique does not give quantitative information about the phase distribution within the object. 7 However, many quantitative phase microscopy modalities have been developed to allow the reconstruction of the amplitude and phase of optically transparent samples.…”